diff --git a/api/urls.py b/api/urls.py
index c4362fcef..a06fb17d6 100644
--- a/api/urls.py
+++ b/api/urls.py
@@ -8,6 +8,7 @@
     path("tasks/<int:task_id>", default_view.task_detail),
     path("tasks/<int:task_id>/duplicate", default_view.duplicate_task),
     path("tasks/", default_view.task_detail),
+    path("classrooms-list/", default_view.classrooms_list),
     path("task-list", default_view.tasks_list_all),
     path("task-list/<subject_abbr>", default_view.tasks_list_all),
     path("student-list", default_view.student_list),
diff --git a/api/views/default.py b/api/views/default.py
index fce7f72db..5cae7019f 100644
--- a/api/views/default.py
+++ b/api/views/default.py
@@ -47,8 +47,15 @@
     assignedtask_results,
     current_semester,
     submit_assignment_path,
+    ClassroomIpRange,
+)
+from common.submit import (
+    SubmitRateLimited,
+    store_submit,
+    SubmitPastHardDeadline,
+    SubmitAfterFinal,
+    SubmitFromUnauthorizedIPError,
 )
-from common.submit import SubmitRateLimited, store_submit, SubmitPastHardDeadline, SubmitAfterFinal
 from common.upload import MAX_UPLOAD_FILECOUNT, TooManyFilesError
 from common.utils import is_teacher, points_to_color, inbus_search_user, user_from_inbus_person
 from quiz.models import EnrolledQuiz
@@ -597,6 +604,12 @@ def add_student_to_class(request, class_id):
     )
 
 
+def classrooms_list(request):
+    classrooms = ClassroomIpRange.objects.values("id", "name")
+
+    return JsonResponse(list(classrooms), safe=False)
+
+
 @user_passes_test(is_teacher)
 def task_detail(request, task_id=None):
     errors = []
@@ -719,7 +732,7 @@ def set_subject(task):
 
         for cl in data["classes"]:
             if cl.get("assigned", None):
-                AssignedTask.objects.update_or_create(
+                assigned_task, _ = AssignedTask.objects.update_or_create(
                     task_id=task.pk,
                     clazz_id=cl["id"],
                     defaults={
@@ -731,6 +744,15 @@ def set_subject(task):
                         "hard_deadline": cl.get("hard_deadline", False),
                     },
                 )
+
+                if "allowed_classrooms" in cl:
+                    classes = []
+                    for class_id in cl["allowed_classrooms"]:
+                        class_object = ClassroomIpRange.objects.get(pk=class_id)
+                        classes.append(class_object)
+
+                    assigned_task.allowed_classrooms.set(classes)
+
             else:
                 submits = Submit.objects.filter(
                     assignment__task_id=task.pk, assignment__clazz_id=cl["id"]
@@ -856,6 +878,9 @@ def is_allowed(path):
             item["deadline"] = assigned.deadline
             item["max_points"] = assigned.max_points
             item["hard_deadline"] = assigned.hard_deadline
+            item["allowed_classrooms"] = list(
+                assigned.allowed_classrooms.values_list("id", flat=True)
+            )
 
         result["classes"].append(item)
 
@@ -1024,6 +1049,12 @@ def create_submit(request: django.http.HttpRequest, task_assignment: int) -> Jso
                 "error": "The submission was sent after the final one, so it is not a valid submission."
             }
         )
+    except SubmitFromUnauthorizedIPError:
+        return JsonResponse(
+            {
+                "error": "The submission was sent from IP address that is not on the list of allowed IP addresses."
+            }
+        )
 
     url = (
         reverse(
diff --git a/common/admin.py b/common/admin.py
index 9d9e2ae0f..b0bdd346e 100644
--- a/common/admin.py
+++ b/common/admin.py
@@ -1,7 +1,11 @@
+import ipaddress
+
 from django.contrib import admin
 from django.contrib.auth.admin import UserAdmin
 from django.contrib.auth.models import User
 
+from django import forms
+
 import common.models as models
 import common.utils
 
@@ -82,6 +86,8 @@ class AssignedTaskAdmin(admin.ModelAdmin):
     autocomplete_fields = ["task", "clazz"]
     search_fields = ["task__name", "clazz__teacher__username", "clazz__subject_abbr"]
 
+    filter_horizontal = ["allowed_classrooms"]
+
     def formfield_for_foreignkey(self, db_field, request, **kwargs):
         if db_field.name == "clazz":
             kwargs["queryset"] = models.Class.objects.current_semester()
@@ -138,6 +144,56 @@ class SubmitAdmin(admin.ModelAdmin):
     autocomplete_fields = ["assignment"]
 
 
+class ClassroomAdminForm(forms.ModelForm):
+    use_cidr = forms.BooleanField(required=False, label="Enter CIDR instead of range")
+
+    ip_range_start = forms.GenericIPAddressField(required=False)
+    ip_range_end = forms.GenericIPAddressField(required=False)
+    cidr = forms.CharField(required=False, label="CIDR address")
+
+    class Meta:
+        model = models.ClassroomIpRange
+        fields = ("name", "ip_range_start", "ip_range_end", "cidr")
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        if self.instance and self.instance.pk:
+            start_ip = ipaddress.ip_address(self.instance.ip_range_start)
+            end_ip = ipaddress.ip_address(self.instance.ip_range_end)
+
+            cidr = list(ipaddress.summarize_address_range(start_ip, end_ip))[0]
+
+            self.fields["cidr"].initial = str(cidr)
+
+    def clean(self):
+        cleaned_data = super().clean()
+
+        if cleaned_data.get("name") is None:
+            raise forms.ValidationError("Please enter classroom code")
+
+        cidr = cleaned_data.get("use_cidr")
+
+        if cidr:
+            cidr_value = cleaned_data.get("cidr")
+            if not cidr_value:
+                raise forms.ValidationError("Cannot read CIDR field value")
+
+            network = ipaddress.ip_network(cidr_value, strict=False)
+
+            cleaned_data["ip_range_start"] = network.network_address
+            cleaned_data["ip_range_end"] = network.broadcast_address
+        else:
+            if not cleaned_data.get("ip_range_start") or not cleaned_data.get("ip_range_end"):
+                raise forms.ValidationError("You didn't enter IP range")
+
+        return cleaned_data
+
+
+class ClassroomAdmin(admin.ModelAdmin):
+    form = ClassroomAdminForm
+
+
 admin.site.register(models.Task, TaskAdmin)
 admin.site.register(models.Class, ClassAdmin)
 admin.site.register(models.Submit, SubmitAdmin)
@@ -145,6 +201,7 @@ class SubmitAdmin(admin.ModelAdmin):
 admin.site.register(models.Semester)
 admin.site.register(models.Subject)
 admin.site.register(models.UserEventModel)
+admin.site.register(models.ClassroomIpRange, ClassroomAdmin)
 
 admin.site.unregister(User)
 admin.site.register(User, MyUserAdmin)
diff --git a/common/migrations/0030_classroomiprange_assignedtask_allowed_classrooms.py b/common/migrations/0030_classroomiprange_assignedtask_allowed_classrooms.py
new file mode 100644
index 000000000..5de87f627
--- /dev/null
+++ b/common/migrations/0030_classroomiprange_assignedtask_allowed_classrooms.py
@@ -0,0 +1,27 @@
+# Generated by Django 4.2.16 on 2025-10-23 12:06
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('common', '0029_submit_is_final_alter_usereventmodel_action'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ClassroomIpRange',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.TextField()),
+                ('ip_range_start', models.GenericIPAddressField()),
+                ('ip_range_end', models.GenericIPAddressField()),
+            ],
+        ),
+        migrations.AddField(
+            model_name='assignedtask',
+            name='allowed_classrooms',
+            field=models.ManyToManyField(related_name='assignments', to='common.classroomiprange'),
+        ),
+    ]
diff --git a/common/models.py b/common/models.py
index 8497478e8..350f7f055 100644
--- a/common/models.py
+++ b/common/models.py
@@ -1,3 +1,4 @@
+import ipaddress
 import os
 import re
 import logging
@@ -222,6 +223,15 @@ class Meta:
         verbose_name_plural = "classes"
 
 
+class ClassroomIpRange(models.Model):
+    name = models.TextField()
+    ip_range_start = models.GenericIPAddressField()
+    ip_range_end = models.GenericIPAddressField()
+
+    def __str__(self):
+        return f"{self.name}: {self.ip_range_start} – {self.ip_range_end}"
+
+
 class AssignedTask(models.Model):
     task = models.ForeignKey(Task, on_delete=models.CASCADE)
     clazz = models.ForeignKey(Class, on_delete=models.CASCADE)
@@ -230,6 +240,7 @@ class AssignedTask(models.Model):
     hard_deadline = models.BooleanField(default=False)
     max_points = models.IntegerField(null=True, blank=True)
     moss_url = models.URLField(null=True, blank=True, editable=False)
+    allowed_classrooms = models.ManyToManyField(ClassroomIpRange, related_name="assignments")
 
     def is_visible(self):
         return timezone.now() >= self.assigned
@@ -243,6 +254,22 @@ def is_past_deadline(self):
             and datetime.datetime.now(datetime.timezone.utc) > self.deadline
         )
 
+    def is_allowed_from_ip(self, ip: str) -> bool:
+        ip = ipaddress.ip_address(ip)
+
+        if not self.allowed_classrooms.all().exists():
+            return True
+
+        allowed = False
+
+        for classroom in self.allowed_classrooms.all():
+            start = ipaddress.ip_address(classroom.ip_range_start)
+            end = ipaddress.ip_address(classroom.ip_range_end)
+
+            allowed |= start <= ip <= end
+
+        return allowed
+
     def __str__(self):
         return f"{self.task.name} {self.clazz}"
 
diff --git a/common/submit.py b/common/submit.py
index cbcb188ce..524199c87 100644
--- a/common/submit.py
+++ b/common/submit.py
@@ -35,6 +35,11 @@ def __init__(self, message: str):
         super().__init__(message)
 
 
+class SubmitFromUnauthorizedIPError(Exception):
+    def __init__(self, message: str):
+        super().__init__(message)
+
+
 def store_submit(request: HttpRequest, assignment: AssignedTask) -> Submit:
     """
     Creates a new submit for the given `assignment` and the user logged in the `request`.
@@ -81,6 +86,12 @@ def store_submit(request: HttpRequest, assignment: AssignedTask) -> Submit:
     if client_ip:
         s.ip_address = client_ip
 
+    if assignment.allowed_classrooms:
+        if not assignment.is_allowed_from_ip(client_ip):
+            raise SubmitFromUnauthorizedIPError(
+                "It is forbidden to upload solutions from this IP address"
+            )
+
     solutions = request.FILES.getlist("solution")
     tmp = request.POST.get("paths", None)
     if tmp:
diff --git a/common/utils.py b/common/utils.py
index aea9feba2..53e812e9b 100644
--- a/common/utils.py
+++ b/common/utils.py
@@ -1,5 +1,10 @@
 from datetime import timedelta
+
+from django.core.exceptions import PermissionDenied
 from django.http import HttpRequest
+from django.http.response import Http404
+from django.utils import timezone
+
 from .inbus import inbus
 import django.contrib.auth.models
 import re
@@ -81,3 +86,56 @@ def get_client_ip_address(request: HttpRequest) -> IPAddressString | None:
         return None
     else:
         return IPAddressString(client_ip)
+
+
+def ip_address_check(function):
+    """
+    Decorator that restricts access to specific IP addresses.
+
+    The decorated function must have the following parameters:
+        - request
+        - assignment_id
+
+    Access is granted if any of the following conditions are met:
+        - requesting user is a teacher
+        - assignment deadline has passed
+        - assignment has no IP address restrictions
+        - user is accessing from an allowed IP address
+
+    IP address check is performed using:
+        models.AssignedTask.is_allowed_from_ip(str)
+    """
+
+    def wrapper(*args, **kwargs):
+        # this import is here to prevent cyclic dependency (.models uses is_teacher)
+        from .models import AssignedTask
+
+        request = args[0]
+
+        if is_teacher(request.user):
+            return function(*args, **kwargs)
+
+        assignment_id = kwargs.get("assignment_id")
+
+        try:
+            assignment = AssignedTask.objects.get(pk=assignment_id)
+        except AssignedTask.DoesNotExist:
+            raise Http404(f"AssignedTask with id {assignment_id} not found")
+
+        # allow after deadline
+        if assignment.deadline is not None and timezone.now() > assignment.deadline:
+            return function(*args, **kwargs)
+
+        if assignment.allowed_classrooms:
+            x_forwarded_for = request.META.get("HTTP_X_FORWARDED_FOR")
+            if x_forwarded_for:
+                ip = x_forwarded_for.split(",")[0].strip()
+            else:
+                ip = request.META.get("REMOTE_ADDR")
+
+            if assignment.is_allowed_from_ip(ip):
+                return function(*args, **kwargs)
+            else:
+                raise PermissionDenied("Access from this IP is not allowed")
+
+    return wrapper
diff --git a/frontend/src/ClassroomsSelect.svelte b/frontend/src/ClassroomsSelect.svelte
new file mode 100644
index 000000000..4c4df64ee
--- /dev/null
+++ b/frontend/src/ClassroomsSelect.svelte
@@ -0,0 +1,119 @@
+<script>
+import { onDestroy, onMount } from 'svelte';
+import { fetch } from './api';
+
+export let selected_classrooms = [];
+export let onDuplicateClick;
+
+let all_classrooms = [];
+
+onMount(async () => {
+  const req = await fetch('/api/classrooms-list/');
+  all_classrooms = await req.json();
+});
+
+$: if (selected_classrooms) {
+  all_classrooms = all_classrooms.map((i) => {
+    i.selected = selected_classrooms.includes(i.id);
+    return i;
+  });
+}
+
+let search = '';
+let showDropdown = false;
+
+function toggleItem(item) {
+  item.selected = !item.selected;
+  if (item.selected) {
+    selected_classrooms.push(item.id);
+  } else {
+    const idx = selected_classrooms.indexOf(item.id);
+    if (idx > -1) {
+      selected_classrooms.splice(idx, 1);
+    }
+  }
+  all_classrooms = [...all_classrooms];
+  selected_classrooms = [...selected_classrooms];
+}
+
+$: sortedClassroomList = all_classrooms
+  .filter((i) => i.name.toLowerCase().includes(search.toLowerCase()))
+  .sort((a, b) => {
+    if (a.selected && !b.selected) return -1;
+    if (!a.selected && b.selected) return 1;
+
+    return a.name.localeCompare(b.name);
+  });
+
+$: selectedCount = all_classrooms.filter((i) => i.selected).length;
+
+function toggleDropdown() {
+  showDropdown = !showDropdown;
+  if (showDropdown) {
+    document.addEventListener('click', handleClickOutside);
+  } else {
+    document.removeEventListener('click', handleClickOutside);
+  }
+}
+
+let outsideClick;
+function handleClickOutside(event) {
+  if (outsideClick && !outsideClick.contains(event.target)) {
+    showDropdown = false;
+    document.removeEventListener('click', handleClickOutside);
+  }
+}
+
+onDestroy(() => {
+  document.removeEventListener('click', handleClickOutside);
+});
+</script>
+
+<div class="dropdown" style="position: relative;" bind:this={outsideClick}>
+  <div class="input-group">
+    <input
+      type="button"
+      value={selectedCount > 0 ? `${selectedCount} classroom(s) selected` : 'Select classrooms'}
+      class="btn btn-sm btn-primary"
+      on:click={toggleDropdown} />
+    <button
+      class="btn btn-sm btn-secondary"
+      title="Set assigned classroom list to all visible classes"
+      on:click|preventDefault={() => onDuplicateClick(selected_classrooms)}>
+      <span class="iconify" data-icon="mdi:content-duplicate"></span>
+    </button>
+  </div>
+
+  {#if showDropdown}
+    <div
+      class="card p-3 mt-2"
+      style="position: absolute; z-index: 1000; width: 250px; max-height: 300px; overflow-y: auto;">
+      <input type="text" placeholder="Search..." bind:value={search} class="form-control mb-2" />
+
+      {#each sortedClassroomList as classroom (classroom.id)}
+        <div class="form-check">
+          <input
+            type="checkbox"
+            class="form-check-input"
+            id={'classroom' + classroom.id}
+            checked={classroom.selected}
+            on:change={() => toggleItem(classroom)} />
+          <label class="form-check-label" for={'classroom' + classroom.id}>{classroom.name}</label>
+        </div>
+      {/each}
+
+      {#if sortedClassroomList.length === 0}
+        <small class="text-black">No classrooms found</small>
+      {/if}
+    </div>
+  {/if}
+</div>
+
+<style>
+.dropdown .card {
+  background: white;
+  border: 1px solid #ddd;
+  border-radius: 0.25rem;
+  color: black;
+}
+</style>
diff --git a/frontend/src/EditTask.svelte b/frontend/src/EditTask.svelte
index 58301600b..61c954a83 100644
--- a/frontend/src/EditTask.svelte
+++ b/frontend/src/EditTask.svelte
@@ -10,6 +10,7 @@ import { fs, currentPath, cwd, openedFiles } from './fs.js';
 import SyncLoader from './SyncLoader.svelte';
 import Modal from './Modal.svelte';
 import { task_types } from './taskTypes';
+import ClassroomsSelect from './ClassroomsSelect.svelte';
 
 export let params = {};
 
@@ -189,6 +190,15 @@ function assignHardDeadlineToAll(hard_deadline) {
   });
 }
 
+function assignClassesToAll(classes) {
+  task.classes = task.classes.map((cl) => {
+    if (cl.assigned) {
+      cl.allowed_classrooms = structuredClone(classes);
+    }
+    return cl;
+  });
+}
+
 function assignSameToAll(templateClass) {
   task.classes = task.classes.map((cl) => {
     if (isClassVisible(cl)) {
@@ -196,6 +206,7 @@ function assignSameToAll(templateClass) {
       cl.assigned = templateClass.assigned;
       cl.deadline = templateClass.deadline;
       cl.hard_deadline = templateClass.hard_deadline;
+      cl.allowed_classrooms = structuredClone(templateClass.allowed_classrooms);
     }
     return cl;
   });
@@ -334,9 +345,9 @@ async function deleteTask(proceed) {
                         onToRelativeClick={setRelativeDeadlineToAssigned} />
                       {#if clazz.deadline}
                         <div
-                          class="col-md"
+                          class="col-2"
                           title="Forbids students to make submissions after the deadline has passed.">
-                          <div class="input-group input-group-sm col-md">
+                          <div class="input-group input-group-sm">
                             <input
                               class="form-check-input checkbox-md"
                               type="checkbox"
@@ -354,7 +365,7 @@ async function deleteTask(proceed) {
                           </div>
                         </div>
                       {/if}
-                      <div class="col-md">
+                      <div class="col-2">
                         <div class="input-group">
                           <input
                             class="form-control form-control-sm"
@@ -373,6 +384,13 @@ async function deleteTask(proceed) {
                           </button>
                         </div>
                       </div>
+                      {#if task.type === 'exam' && clazz.assigned}
+                        <div class="col-2">
+                          <ClassroomsSelect
+                            bind:selected_classrooms={clazz.allowed_classrooms}
+                            onDuplicateClick={assignClassesToAll}></ClassroomsSelect>
+                        </div>
+                      {/if}
                     </div>
                   </td>
                   <td>
diff --git a/frontend/src/TimeRange.svelte b/frontend/src/TimeRange.svelte
index 5afc90609..5b51a903f 100644
--- a/frontend/src/TimeRange.svelte
+++ b/frontend/src/TimeRange.svelte
@@ -58,63 +58,67 @@ $: if (instanceTo) {
 }
 </script>
 
-<div class="input-group input-group-sm col-md">
-  <button
-    class="btn btn-primary dropdown-toggle"
-    data-bs-toggle="dropdown"
-    type="button"
-    aria-expanded="false"></button>
-  <ul class="dropdown-menu">
-    <button class="dropdown-item" on:click={() => (from = new Date())}>Now</button>
-    {#each { length: 14 } as _, i}
-      <button class="dropdown-item" on:click={() => (from = weekDate(i))}>
-        Week {i + 1}
-        {#if weekStart(i) <= new Date() && new Date() <= weekStart(i + 1)}
-          <span><span class="iconify" data-icon="akar-icons:arrow-back"></span></span>
-        {/if}
-      </button>
-    {/each}
-  </ul>
-  <input bind:this={fromEl} class="form-control" bind:value={from} placeholder="Assigned" />
-  <button
-    class="btn btn-sm btn-secondary"
-    title="Set assigned date to all visible classes"
-    disabled={!from}
-    on:click|preventDefault={() => onFromDuplicateClick(from)}>
-    <span class="iconify" data-icon="mdi:content-duplicate"></span>
-  </button>
+<div class="col">
+  <div class="input-group input-group-sm">
+    <button
+      class="btn btn-primary dropdown-toggle"
+      data-bs-toggle="dropdown"
+      type="button"
+      aria-expanded="false"></button>
+    <ul class="dropdown-menu">
+      <button class="dropdown-item" on:click={() => (from = new Date())}>Now</button>
+      {#each { length: 14 } as _, i}
+        <button class="dropdown-item" on:click={() => (from = weekDate(i))}>
+          Week {i + 1}
+          {#if weekStart(i) <= new Date() && new Date() <= weekStart(i + 1)}
+            <span><span class="iconify" data-icon="akar-icons:arrow-back"></span></span>
+          {/if}
+        </button>
+      {/each}
+    </ul>
+    <input bind:this={fromEl} class="form-control" bind:value={from} placeholder="Assigned" />
+    <button
+      class="btn btn-sm btn-secondary"
+      title="Set assigned date to all visible classes"
+      disabled={!from}
+      on:click|preventDefault={() => onFromDuplicateClick(from)}>
+      <span class="iconify" data-icon="mdi:content-duplicate"></span>
+    </button>
+  </div>
 </div>
 
-<div class="input-group input-group-sm col-md">
-  <button
-    class="btn btn-primary dropdown-toggle"
-    data-bs-toggle="dropdown"
-    type="button"
-    aria-expanded="false"
-    disabled={!from}></button>
-  <ul class="dropdown-menu">
-    <button class="dropdown-item" on:click={() => addDeadline(30)}>+ 30 min</button>
-    <button class="dropdown-item" on:click={() => addDeadline(1 * 45)}>+ 1×45 min</button>
-    <button class="dropdown-item" on:click={() => addDeadline(2 * 45)}>+ 2×45 min</button>
-    <button class="dropdown-item" on:click={() => addDeadline(3 * 45)}>+ 3×45 min</button>
-    <button class="dropdown-item" on:click={() => addDeadline(1 * 60)}>+ 1×60 min</button>
-    <button class="dropdown-item" on:click={() => addDeadline(2 * 60)}>+ 2×60 min</button>
-    <button class="dropdown-item" on:click={() => addDeadline(3 * 60)}>+ 3×60 min</button>
-    <button class="dropdown-item" on:click={() => addDeadline(60 * 24 * 7)}>+ week</button>
-  </ul>
-  <input bind:this={toEl} class="form-control" bind:value={to} placeholder="Deadline" />
-  <button
-    class="btn btn-sm btn-secondary"
-    title="Set deadline to all assigned classes"
-    disabled={!to}
-    on:click|preventDefault={() => onToDuplicateClick(to)}>
-    <span class="iconify" data-icon="mdi:content-duplicate"></span>
-  </button>
-  <button
-    class="btn btn-sm btn-secondary"
-    title="Set relative deadline to all assigned classes"
-    disabled={!to}
-    on:click|preventDefault={() => onToRelativeClick(from, to)}>
-    <span class="iconify" data-icon="mdi:calendar-sync"></span>
-  </button>
+<div class="col">
+  <div class="input-group input-group-sm">
+    <button
+      class="btn btn-primary dropdown-toggle"
+      data-bs-toggle="dropdown"
+      type="button"
+      aria-expanded="false"
+      disabled={!from}></button>
+    <ul class="dropdown-menu">
+      <button class="dropdown-item" on:click={() => addDeadline(30)}>+ 30 min</button>
+      <button class="dropdown-item" on:click={() => addDeadline(1 * 45)}>+ 1×45 min</button>
+      <button class="dropdown-item" on:click={() => addDeadline(2 * 45)}>+ 2×45 min</button>
+      <button class="dropdown-item" on:click={() => addDeadline(3 * 45)}>+ 3×45 min</button>
+      <button class="dropdown-item" on:click={() => addDeadline(1 * 60)}>+ 1×60 min</button>
+      <button class="dropdown-item" on:click={() => addDeadline(2 * 60)}>+ 2×60 min</button>
+      <button class="dropdown-item" on:click={() => addDeadline(3 * 60)}>+ 3×60 min</button>
+      <button class="dropdown-item" on:click={() => addDeadline(60 * 24 * 7)}>+ week</button>
+    </ul>
+    <input bind:this={toEl} class="form-control" bind:value={to} placeholder="Deadline" />
+    <button
+      class="btn btn-sm btn-secondary"
+      title="Set deadline to all assigned classes"
+      disabled={!to}
+      on:click|preventDefault={() => onToDuplicateClick(to)}>
+      <span class="iconify" data-icon="mdi:content-duplicate"></span>
+    </button>
+    <button
+      class="btn btn-sm btn-secondary"
+      title="Set relative deadline to all assigned classes"
+      disabled={!to}
+      on:click|preventDefault={() => onToRelativeClick(from, to)}>
+      <span class="iconify" data-icon="mdi:calendar-sync"></span>
+    </button>
+  </div>
 </div>
diff --git a/web/views/student.py b/web/views/student.py
index 462a21201..4f2e7c91d 100644
--- a/web/views/student.py
+++ b/web/views/student.py
@@ -53,7 +53,7 @@
 from common.plagcheck.moss import PlagiarismMatch, moss_result
 from common.submit import SubmitRateLimited, store_submit, SubmitPastHardDeadline
 from common.upload import MAX_UPLOAD_FILECOUNT, TooManyFilesError
-from common.utils import is_teacher
+from common.utils import is_teacher, ip_address_check
 from evaluator.results import EvaluationResult
 from evaluator.testsets import TestSet
 from kelvin.settings import BASE_DIR, MAX_INLINE_CONTENT_BYTES, MAX_INLINE_LINES
@@ -314,6 +314,7 @@ def build(match: PlagiarismMatch) -> PlagiarismEntry:
 
 
 @login_required()
+@ip_address_check
 def task_detail(request, assignment_id, submit_num=None, login=None):
     submits = Submit.objects.filter(
         assignment__pk=assignment_id,
@@ -545,6 +546,7 @@ def submit_source(request, submit_id, path):
 
 
 @login_required
+@ip_address_check
 def submit_diff(request, login, assignment_id, submit_a, submit_b):
     submit = get_object_or_404(
         Submit, assignment_id=assignment_id, student__username=login, submit_num=submit_a
@@ -608,6 +610,7 @@ def get_patch(p1, p2):
 
 
 @login_required
+@ip_address_check
 def submit_comments(request, assignment_id, login, submit_num):
     submit = get_object_or_404(
         Submit, assignment_id=assignment_id, student__username=login, submit_num=submit_num
@@ -1045,11 +1048,13 @@ def submit_download(request, assignment_id: int, login: str, submit_num: int):
 
 
 @login_required
+@ip_address_check
 def ui(request):
     return render(request, "web/ui.html")
 
 
 @csrf_exempt
+@ip_address_check
 def upload_results(request, assignment_id, submit_num, login):
     submit = get_object_or_404(
         Submit, assignment_id=assignment_id, submit_num=submit_num, student__username=login
@@ -1079,6 +1084,7 @@ def upload_results(request, assignment_id, submit_num, login):
 
 
 @login_required()
+@ip_address_check
 def mark_solution_as_final(request, assignment_id, login, submit_num):
     submit = get_object_or_404(
         Submit, assignment_id=assignment_id, submit_num=submit_num, student__username=login