add ssh affected user resolve

management/server/account.go

@@ -1629,6 +1629,7 @@ func (am *DefaultAccountManager) SyncUserJWTGroups(ctx context.Context, userAuth
 	var user *types.User
 	var change affectedpeers.Change
 	var snap *affectedpeers.Snapshot
+	var requiresAccountUpdate bool
 	err = am.Store.ExecuteInTransaction(ctx, func(transaction store.Store) error {
 		user, err = transaction.GetUserByUserID(ctx, store.LockingStrengthNone, userAuth.UserId)
 		if err != nil {
@@ -1668,6 +1669,9 @@ func (am *DefaultAccountManager) SyncUserJWTGroups(ctx context.Context, userAuth
 		}
 
 		allGroupChanges := slices.Concat(addNewGroups, removeOldGroups)
+		// The user's auto-groups changed, so the SSH rules authorizing them ship a new
+		// group -> user mapping even when no peer moves between groups.
+		change.UserGroupIDs = allGroupChanges
 
 		// Propagate changes to peers if group propagation is enabled
 		if settings.GroupsPropagationEnabled {
@@ -1692,16 +1696,9 @@ func (am *DefaultAccountManager) SyncUserJWTGroups(ctx context.Context, userAuth
 
 			change.LinkGroups = allGroupChanges
 
-			// An IPv6 reconcile can change the peers' addresses, which are visible
-			// through ALL their group memberships, so seed the full walk instead of
-			// folding the peers alone.
-			for _, g := range allGroupChanges {
-				if slices.Contains(settings.IPv6EnabledGroups, g) {
-					change.ChangedPeerIDs = change.OutputPeerIDs
-					change.OutputPeerIDs = nil
-					break
-				}
-			}
+			// The reconciliation reassigns IPv6 addresses across the account, which
+			// every peer that can reach the reassigned ones observes.
+			requiresAccountUpdate = ipv6ReconcileNeeded(settings, allGroupChanges)
 
 			if err = am.reconcileIPv6ForGroupChanges(ctx, transaction, userAuth.AccountId, allGroupChanges); err != nil {
 				return fmt.Errorf("reconcile IPv6 for group changes: %w", err)
@@ -1712,16 +1709,6 @@ func (am *DefaultAccountManager) SyncUserJWTGroups(ctx context.Context, userAuth
 			}
 		}
 
-		// The user->group mapping shipped to SSH destination peers (GroupIDToUserIDs)
-		// changed for these groups even without peer propagation, so the destinations
-		// of SSH rules authorizing them must refresh.
-		sshDistributionGroups, sshPeerIDs, err := sshAuthorizedGroupConsumers(ctx, transaction, userAuth.AccountId, allGroupChanges)
-		if err != nil {
-			return err
-		}
-		change.DistributionGroupIDs = sshDistributionGroups
-		change.OutputPeerIDs = append(change.OutputPeerIDs, sshPeerIDs...)
-
 		if snap, err = affectedpeers.Load(ctx, transaction, userAuth.AccountId, change); err != nil {
 			return err
 		}
@@ -1762,6 +1749,12 @@ func (am *DefaultAccountManager) SyncUserJWTGroups(ctx context.Context, userAuth
 		}
 	}
 
+	if requiresAccountUpdate {
+		log.WithContext(ctx).Tracef("user %s: JWT group membership changed, updating account peers", userAuth.UserId)
+		am.BufferUpdateAccountPeers(ctx, userAuth.AccountId, types.UpdateReason{Resource: types.UpdateResourceUser, Operation: types.UpdateOperationUpdate})
+		return nil
+	}
+
 	log.WithContext(ctx).Tracef("user %s: JWT group membership changed, updating affected peers", userAuth.UserId)
 	bgCtx := context.WithoutCancel(ctx)
 	go func() {
@@ -1777,53 +1770,6 @@ func (am *DefaultAccountManager) SyncUserJWTGroups(ctx context.Context, userAuth
 	return nil
 }
 
-// sshAuthorizedGroupConsumers returns the destination groups and destination peers of
-// enabled SSH rules whose AuthorizedGroups reference any of the changed groups. Their
-// network maps carry the user->group mapping for those groups.
-func sshAuthorizedGroupConsumers(ctx context.Context, transaction store.Store, accountID string, changedGroupIDs []string) ([]string, []string, error) {
-	if len(changedGroupIDs) == 0 {
-		return nil, nil, nil
-	}
-
-	policies, err := transaction.GetAccountPolicies(ctx, store.LockingStrengthNone, accountID)
-	if err != nil {
-		return nil, nil, fmt.Errorf("error getting account policies: %w", err)
-	}
-
-	changed := make(map[string]struct{}, len(changedGroupIDs))
-	for _, id := range changedGroupIDs {
-		changed[id] = struct{}{}
-	}
-
-	var groupIDs []string
-	var peerIDs []string
-	for _, policy := range policies {
-		if policy == nil || !policy.Enabled {
-			continue
-		}
-		for _, rule := range policy.Rules {
-			if !rule.Enabled || rule.Protocol != types.PolicyRuleProtocolNetbirdSSH {
-				continue
-			}
-			authorized := false
-			for groupID := range rule.AuthorizedGroups {
-				if _, ok := changed[groupID]; ok {
-					authorized = true
-					break
-				}
-			}
-			if !authorized {
-				continue
-			}
-			groupIDs = append(groupIDs, rule.Destinations...)
-			if rule.DestinationResource.Type == types.ResourceTypePeer && rule.DestinationResource.ID != "" {
-				peerIDs = append(peerIDs, rule.DestinationResource.ID)
-			}
-		}
-	}
-	return groupIDs, peerIDs, nil
-}
-
 // getAccountIDWithAuthorizationClaims retrieves an account ID using JWT Claims.
 // if domain is not private or domain is invalid, it will return the account ID by user ID.
 // if domain is of the PrivateCategory category, it will evaluate
@@ -2502,30 +2448,27 @@ func (am *DefaultAccountManager) reconcileIPv6ForGroupChanges(ctx context.Contex
 		return fmt.Errorf("get account settings: %w", err)
 	}
 
-	if len(settings.IPv6EnabledGroups) == 0 {
-		return nil
-	}
-
-	enabledSet := make(map[string]struct{}, len(settings.IPv6EnabledGroups))
-	for _, gid := range settings.IPv6EnabledGroups {
-		enabledSet[gid] = struct{}{}
-	}
-
-	affected := false
-	for _, gid := range groupIDs {
-		if _, ok := enabledSet[gid]; ok {
-			affected = true
-			break
-		}
-	}
-
-	if !affected {
+	if !ipv6ReconcileNeeded(settings, groupIDs) {
 		return nil
 	}
 
 	return am.updatePeerIPv6Addresses(ctx, transaction, accountID, settings)
 }
 
+// ipv6ReconcileNeeded reports whether changes to the given groups trigger an IPv6
+// reconciliation. A reconciliation reassigns addresses across the whole account, and a
+// peer's address is visible to everyone that reaches it through any of its groups, so
+// callers that otherwise compute an affected-peers set must fall back to updating the
+// whole account.
+func ipv6ReconcileNeeded(settings *types.Settings, groupIDs []string) bool {
+	for _, groupID := range groupIDs {
+		if slices.Contains(settings.IPv6EnabledGroups, groupID) {
+			return true
+		}
+	}
+	return false
+}
+
 func (am *DefaultAccountManager) ensureIPv6Subnet(ctx context.Context, transaction store.Store, accountID string, settings *types.Settings, network *types.Network) error {
 	if settings.NetworkRangeV6.IsValid() {
 		network.NetV6 = net.IPNet{

management/server/affected_peers_jwt_test.go

@@ -8,12 +8,81 @@ import (
 	"github.com/stretchr/testify/require"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
+	"github.com/netbirdio/netbird/management/server/affectedpeers"
 	nbpeer "github.com/netbirdio/netbird/management/server/peer"
 	"github.com/netbirdio/netbird/management/server/store"
 	"github.com/netbirdio/netbird/management/server/types"
 	"github.com/netbirdio/netbird/shared/auth"
 )
 
+// A user's auto-group change refreshes the destinations of the SSH rules authorizing
+// that group — they carry the group -> user mapping — even though no peer moved
+// between groups.
+func TestAffectedPeers_UserGroupChange_RefreshesSSHAuthorizedDestinations(t *testing.T) {
+	manager, s, accountID, peerIDs, groupIDs := setupAffectedPeersTest(t)
+	ctx := context.Background()
+
+	_, err := manager.SavePolicy(ctx, accountID, userID, &types.Policy{
+		Enabled: true,
+		Rules: []*types.PolicyRule{
+			{
+				Enabled:          true,
+				Sources:          []string{groupIDs[0]},
+				Destinations:     []string{groupIDs[1]},
+				Protocol:         types.PolicyRuleProtocolNetbirdSSH,
+				Action:           types.PolicyTrafficActionAccept,
+				AuthorizedGroups: map[string][]string{groupIDs[3]: {"root"}},
+			},
+		},
+	}, true)
+	require.NoError(t, err)
+
+	result := resolveAffected(t, s, accountID, affectedpeers.Change{UserGroupIDs: []string{groupIDs[3]}})
+	assert.ElementsMatch(t, []string{peerIDs[1]}, result,
+		"only the SSH rule's destination peers carry the changed group -> user mapping")
+
+	result = resolveAffected(t, s, accountID, affectedpeers.Change{UserGroupIDs: []string{groupIDs[4]}})
+	assert.Empty(t, result, "a group no SSH rule authorizes affects nobody")
+}
+
+// Creating, blocking or unblocking a user changes the account's allowed-user set, which
+// reaches only the destinations of the SSH rules that ship it.
+func TestAffectedPeers_AllowedUsersChange_RefreshesSSHDestinations(t *testing.T) {
+	manager, s, accountID, peerIDs, groupIDs := setupAffectedPeersTest(t)
+	ctx := context.Background()
+
+	// Ships the allowed-user set: an SSH rule naming no groups and no user.
+	_, err := manager.SavePolicy(ctx, accountID, userID, &types.Policy{
+		Enabled: true,
+		Rules: []*types.PolicyRule{{
+			Enabled:      true,
+			Sources:      []string{groupIDs[0]},
+			Destinations: []string{groupIDs[1]},
+			Protocol:     types.PolicyRuleProtocolNetbirdSSH,
+			Action:       types.PolicyTrafficActionAccept,
+		}},
+	}, true)
+	require.NoError(t, err)
+
+	// Does not ship it: an SSH rule that authorizes a specific group.
+	_, err = manager.SavePolicy(ctx, accountID, userID, &types.Policy{
+		Enabled: true,
+		Rules: []*types.PolicyRule{{
+			Enabled:          true,
+			Sources:          []string{groupIDs[2]},
+			Destinations:     []string{groupIDs[3]},
+			Protocol:         types.PolicyRuleProtocolNetbirdSSH,
+			Action:           types.PolicyTrafficActionAccept,
+			AuthorizedGroups: map[string][]string{groupIDs[0]: {"root"}},
+		}},
+	}, true)
+	require.NoError(t, err)
+
+	result := resolveAffected(t, s, accountID, affectedpeers.Change{AllowedUsersChanged: true})
+	assert.ElementsMatch(t, []string{peerIDs[1]}, result,
+		"only the destinations of the rule shipping the allowed-user set refresh")
+}
+
 // TestAffectedPeers_SyncUserJWTGroups_OnlyAffectedPeersUpdated verifies that a JWT
 // auto-group change updates only the user's peers and the peers linked to the changed
 // group through policies, instead of fanning out to the whole account.

management/server/affectedpeers/resolver.go

@@ -18,6 +18,7 @@ import (
 	"context"
 
 	log "github.com/sirupsen/logrus"
+	"golang.org/x/exp/maps"
 
 	nbdns "github.com/netbirdio/netbird/dns"
 	rpservice "github.com/netbirdio/netbird/management/internals/modules/reverseproxy/service"
@@ -83,7 +84,7 @@ func (snap *Snapshot) loadCollections(ctx context.Context, s store.Store, accoun
 	hasGroupOrPeerChange := len(c.ChangedGroupIDs) > 0 || len(c.ChangedPeerIDs) > 0 || len(c.LinkGroups) > 0 || len(c.Resources) > 0
 	hasNetworkObject := len(c.Routers) > 0 || len(c.Resources) > 0 || len(c.Networks) > 0
 	// the resource<->router bridge can fire for any of these
-	needsRoutersResources := hasGroupOrPeerChange || len(c.PostureCheckIDs) > 0 || len(c.Policies) > 0 || hasNetworkObject
+	needsRoutersResources := hasGroupOrPeerChange || len(c.PostureCheckIDs) > 0 || len(c.Policies) > 0 || hasNetworkObject || len(c.UserGroupIDs) > 0 || c.AllowedUsersChanged
 
 	if needsRoutersResources {
 		if err := snap.loadPolicyRoutersResources(ctx, s, accountID); err != nil {
@@ -219,6 +220,18 @@ type Change struct {
 	// (correct when the peer's own attributes changed, e.g. IP/status).
 	OutputPeerIDs []string
 
+	// UserGroupIDs are groups whose USER membership changed (a user's auto-groups),
+	// as opposed to their peer membership. Peers ship the group -> user mapping only
+	// for the groups an SSH rule authorizes, so these refresh the destinations of the
+	// SSH rules authorizing them — independently of any peer moving between groups.
+	UserGroupIDs []string
+
+	// AllowedUsersChanged marks a change to the set of users allowed to open SSH
+	// sessions — a user was created, blocked or unblocked. That set is account-wide,
+	// and peers receive it through the SSH rules that name no group or user of their
+	// own, so those rules' destinations refresh.
+	AllowedUsersChanged bool
+
 	// LinkGroups are groups used ONLY to match policies/routes/routers and walk to the
 	// OPPOSITE side — they are never expanded to their own members. Use this when a
 	// peer's group membership changed: pass the peer in ChangedPeerIDs and its
@@ -240,6 +253,8 @@ func (c Change) isEmpty() bool {
 		len(c.Resources) == 0 &&
 		len(c.Networks) == 0 &&
 		len(c.PostureCheckIDs) == 0 &&
+		len(c.UserGroupIDs) == 0 &&
+		!c.AllowedUsersChanged &&
 		len(c.DistributionGroupIDs) == 0 &&
 		len(c.RemovedPeersByGroup) == 0 &&
 		len(c.LinkGroups) == 0 &&
@@ -359,6 +374,9 @@ func (r *resolver) walk() {
 		r.collectFromProxyServices()
 	}
 
+	r.collectFromSSHAuthorizedGroups()
+	r.collectFromAllowedUsers()
+
 	r.collectFromChangedRoutes(r.change.Routes)
 	r.collectFromChangedRouters(r.change.Routers)
 	r.collectFromChangedResources(r.change.Resources)
@@ -811,6 +829,59 @@ func (r *resolver) collectFromNameServers() {
 	}
 }
 
+// collectFromSSHAuthorizedGroups folds the destinations of the enabled SSH rules that
+// authorize a group whose user membership changed. Those destination peers carry the
+// group -> user mapping for the groups they authorize, so they refresh even when no
+// peer moved between groups.
+func (r *resolver) collectFromSSHAuthorizedGroups() {
+	if len(r.change.UserGroupIDs) == 0 {
+		return
+	}
+
+	changed := toSet(r.change.UserGroupIDs)
+	for _, policy := range r.policies() {
+		for _, rule := range policy.Rules {
+			if !rule.Enabled || rule.Protocol != types.PolicyRuleProtocolNetbirdSSH {
+				continue
+			}
+			if !anyInSet(maps.Keys(rule.AuthorizedGroups), changed) {
+				continue
+			}
+			log.WithContext(r.ctx).Tracef("collectFromSSHAuthorizedGroups: rule %s authorizes a changed user group -> folding its destinations", rule.ID)
+			r.foldPolicySideForRule(policy, rule, sideDestination)
+		}
+	}
+}
+
+// collectFromAllowedUsers folds the destinations of the rules that make a peer carry
+// the account's allowed-user set, for a change to who is in that set.
+func (r *resolver) collectFromAllowedUsers() {
+	if !r.change.AllowedUsersChanged {
+		return
+	}
+
+	for _, policy := range r.policies() {
+		for _, rule := range policy.Rules {
+			if !rule.Enabled || !ruleShipsAllowedUsers(rule) {
+				continue
+			}
+			log.WithContext(r.ctx).Tracef("collectFromAllowedUsers: rule %s ships the allowed-user set -> folding its destinations", rule.ID)
+			r.foldPolicySideForRule(policy, rule, sideDestination)
+		}
+	}
+}
+
+// ruleShipsAllowedUsers reports whether a rule makes its destination peers carry the
+// account's allowed-user set. It mirrors the network map's SSH requirements except for
+// the destination peer's own SSH flag, which the snapshot does not hold — so it folds a
+// superset and never misses a peer.
+func ruleShipsAllowedUsers(rule *types.PolicyRule) bool {
+	if rule.Protocol == types.PolicyRuleProtocolNetbirdSSH {
+		return len(rule.AuthorizedGroups) == 0 && rule.AuthorizedUser == ""
+	}
+	return types.PolicyRuleImpliesLegacySSH(rule)
+}
+
 func (r *resolver) collectFromDNSSettings() {
 	if len(r.linkGroups) == 0 || r.snap.dnsSettings == nil {
 		return

management/server/affectedpeers/resolver_test.go

@@ -85,6 +85,8 @@ func TestChangeIsEmpty(t *testing.T) {
 	assert.False(t, Change{Resources: []*resourceTypes.NetworkResource{{ID: "r"}}}.isEmpty())
 	assert.False(t, Change{Networks: []*networkTypes.Network{{ID: "n"}}}.isEmpty())
 	assert.False(t, Change{PostureCheckIDs: []string{"pc"}}.isEmpty())
+	assert.False(t, Change{UserGroupIDs: []string{"g"}}.isEmpty())
+	assert.False(t, Change{AllowedUsersChanged: true}.isEmpty())
 }
 
 func TestPolicyReferencesPostureChecks(t *testing.T) {

management/server/user.go

@@ -593,7 +593,9 @@ func (am *DefaultAccountManager) SaveOrAddUsers(ctx context.Context, accountID,
 		return nil, err
 	}
 
-	var updateAccountPeers bool
+	var requiresAccountUpdate bool
+	var snaps []*affectedpeers.Snapshot
+	var changes []affectedpeers.Change
 	var peersToExpire []*nbpeer.Peer
 	var addUserEvents []func()
 	var usersToSave = make([]*types.User, 0, len(updates))
@@ -629,20 +631,26 @@ func (am *DefaultAccountManager) SaveOrAddUsers(ctx context.Context, accountID,
 		}
 
 		err = am.Store.ExecuteInTransaction(ctx, func(transaction store.Store) error {
-			_, updatedUser, userPeersToExpire, userEvents, err := am.processUserUpdate(
+			effect, updatedUser, userPeersToExpire, userEvents, err := am.processUserUpdate(
 				ctx, transaction, groupsMap, accountID, initiatorUserID, initiatorUser, update, addIfNotExists, settings,
 			)
 			if err != nil {
 				return fmt.Errorf("failed to process update for user %s: %w", update.Id, err)
 			}
 
-			updateAccountPeers = true
-
 			err = transaction.SaveUser(ctx, updatedUser)
 			if err != nil {
 				return fmt.Errorf("failed to save updated user %s: %w", update.Id, err)
 			}
 
+			snap, err := affectedpeers.Load(ctx, transaction, accountID, effect.change)
+			if err != nil {
+				return err
+			}
+
+			requiresAccountUpdate = requiresAccountUpdate || effect.requiresAccountUpdate
+			snaps = append(snaps, snap)
+			changes = append(changes, effect.change)
 			usersToSave = append(usersToSave, updatedUser)
 			addUserEvents = append(addUserEvents, userEvents...)
 			peersToExpire = append(peersToExpire, userPeersToExpire...)
@@ -683,11 +691,15 @@ func (am *DefaultAccountManager) SaveOrAddUsers(ctx context.Context, accountID,
 			log.WithContext(ctx).Errorf("failed update expired peers: %s", err)
 			return nil, err
 		}
-	} else if updateAccountPeers {
+	} else if len(usersToSave) > 0 {
 		if err = am.Store.IncrementNetworkSerial(ctx, accountID); err != nil {
 			return nil, fmt.Errorf("failed to increment network serial: %w", err)
 		}
-		am.UpdateAccountPeers(ctx, accountID, types.UpdateReason{Resource: types.UpdateResourceUser, Operation: types.UpdateOperationUpdate})
+		if requiresAccountUpdate {
+			am.UpdateAccountPeers(ctx, accountID, types.UpdateReason{Resource: types.UpdateResourceUser, Operation: types.UpdateOperationUpdate})
+		} else {
+			go am.dispatchAffected(ctx, accountID, snaps, changes)
+		}
 	}
 
 	return updatedUsersInfo, globalErr
@@ -758,20 +770,31 @@ func (am *DefaultAccountManager) prepareUserUpdateEvents(ctx context.Context, ac
 	return eventsToStore
 }
 
+// userUpdateEffect describes how a user update has to reach peers. Users only enter a
+// network map through the SSH rules, so the change resolves to those rules' peers —
+// except when the update triggers an IPv6 reconciliation, which reassigns addresses
+// across the account and so has to reach everyone.
+type userUpdateEffect struct {
+	change                affectedpeers.Change
+	requiresAccountUpdate bool
+}
+
 func (am *DefaultAccountManager) processUserUpdate(ctx context.Context, transaction store.Store, groupsMap map[string]*types.Group,
-	accountID, initiatorUserId string, initiatorUser, update *types.User, addIfNotExists bool, settings *types.Settings) (bool, *types.User, []*nbpeer.Peer, []func(), error) {
+	accountID, initiatorUserId string, initiatorUser, update *types.User, addIfNotExists bool, settings *types.Settings) (userUpdateEffect, *types.User, []*nbpeer.Peer, []func(), error) {
+
+	var effect userUpdateEffect
 
 	if update == nil {
-		return false, nil, nil, nil, status.Errorf(status.InvalidArgument, "provided user update is nil")
+		return effect, nil, nil, nil, status.Errorf(status.InvalidArgument, "provided user update is nil")
 	}
 
 	oldUser, isNewUser, err := getUserOrCreateIfNotExists(ctx, transaction, accountID, update, addIfNotExists)
 	if err != nil {
-		return false, nil, nil, nil, err
+		return effect, nil, nil, nil, err
 	}
 
 	if err := validateUserUpdate(groupsMap, initiatorUser, oldUser, update); err != nil {
-		return false, nil, nil, nil, err
+		return effect, nil, nil, nil, err
 	}
 
 	// only auto groups, revoked status, and integration reference can be updated for now
@@ -792,13 +815,13 @@ func (am *DefaultAccountManager) processUserUpdate(ctx context.Context, transact
 	var transferredOwnerRole bool
 	result, err := handleOwnerRoleTransfer(ctx, transaction, initiatorUser, update)
 	if err != nil {
-		return false, nil, nil, nil, err
+		return effect, nil, nil, nil, err
 	}
 	transferredOwnerRole = result
 
 	userPeers, err := transaction.GetUserPeers(ctx, store.LockingStrengthNone, updatedUser.AccountID, update.Id)
 	if err != nil {
-		return false, nil, nil, nil, err
+		return effect, nil, nil, nil, err
 	}
 
 	var peersToExpire []*nbpeer.Peer
@@ -807,6 +830,21 @@ func (am *DefaultAccountManager) processUserUpdate(ctx context.Context, transact
 		peersToExpire = userPeers
 	}
 
+	// A user reaches a peer's network map only through the SSH rules: as part of a
+	// group -> user mapping, and as part of the account's allowed-user set. Creating,
+	// blocking or unblocking a user adds it to or removes it from both, so every group
+	// it maps into changes — including the All group that holds every active user.
+	// Otherwise only the auto-groups it joined or left do.
+	if isNewUser || oldUser.IsBlocked() != updatedUser.IsBlocked() {
+		effect.change.AllowedUsersChanged = true
+		effect.change.UserGroupIDs = slices.Concat(oldUser.AutoGroups, updatedUser.AutoGroups, allGroupIDs(groupsMap))
+	} else {
+		effect.change.UserGroupIDs = slices.Concat(
+			util.Difference(oldUser.AutoGroups, updatedUser.AutoGroups),
+			util.Difference(updatedUser.AutoGroups, oldUser.AutoGroups),
+		)
+	}
+
 	var removedGroups, addedGroups []string
 	if update.AutoGroups != nil && settings.GroupsPropagationEnabled {
 		removedGroups = util.Difference(oldUser.AutoGroups, update.AutoGroups)
@@ -814,26 +852,47 @@ func (am *DefaultAccountManager) processUserUpdate(ctx context.Context, transact
 		for _, peer := range userPeers {
 			for _, groupID := range removedGroups {
 				if err := transaction.RemovePeerFromGroup(ctx, peer.ID, groupID); err != nil {
-					return false, nil, nil, nil, fmt.Errorf("failed to remove peer %s from group %s: %w", peer.ID, groupID, err)
+					return effect, nil, nil, nil, fmt.Errorf("failed to remove peer %s from group %s: %w", peer.ID, groupID, err)
 				}
 			}
 			for _, groupID := range addedGroups {
 				if err := transaction.AddPeerToGroup(ctx, accountID, peer.ID, groupID); err != nil {
-					return false, nil, nil, nil, fmt.Errorf("failed to add peer %s to group %s: %w", peer.ID, groupID, err)
+					return effect, nil, nil, nil, fmt.Errorf("failed to add peer %s to group %s: %w", peer.ID, groupID, err)
 				}
 			}
 		}
 
 		allGroupChanges := slices.Concat(removedGroups, addedGroups)
+		if len(allGroupChanges) > 0 {
+			effect.change.LinkGroups = allGroupChanges
+			for _, peer := range userPeers {
+				effect.change.OutputPeerIDs = append(effect.change.OutputPeerIDs, peer.ID)
+			}
+		}
+
+		// The reconciliation reassigns IPv6 addresses across the account, which every
+		// peer that can reach the reassigned ones observes.
+		effect.requiresAccountUpdate = ipv6ReconcileNeeded(settings, allGroupChanges)
+
 		if err := am.reconcileIPv6ForGroupChanges(ctx, transaction, accountID, allGroupChanges); err != nil {
-			return false, nil, nil, nil, fmt.Errorf("reconcile IPv6 for group changes: %w", err)
+			return effect, nil, nil, nil, fmt.Errorf("reconcile IPv6 for group changes: %w", err)
 		}
 	}
 
-	updateAccountPeers := len(userPeers) > 0
 	userEventsToAdd := am.prepareUserUpdateEvents(ctx, updatedUser.AccountID, initiatorUserId, oldUser, updatedUser, transferredOwnerRole, isNewUser, removedGroups, addedGroups, transaction)
 
-	return updateAccountPeers, updatedUser, peersToExpire, userEventsToAdd, nil
+	return effect, updatedUser, peersToExpire, userEventsToAdd, nil
+}
+
+// allGroupIDs returns the ID of the account's All group, which every active user maps
+// into, as a slice so callers can concatenate it.
+func allGroupIDs(groupsMap map[string]*types.Group) []string {
+	for _, group := range groupsMap {
+		if group.IsGroupAll() {
+			return []string{group.ID}
+		}
+	}
+	return nil
 }
 
 // getUserOrCreateIfNotExists retrieves the existing user or creates a new one if it doesn't exist.