diff --git a/hub/api/api.go b/hub/api/api.go
index 844e59e..7c6ac0d 100644
--- a/hub/api/api.go
+++ b/hub/api/api.go
@@ -169,11 +169,25 @@ func (a *API) sweepSessions() {
 }
 
 func (a *API) Network_Create(n *Network) error {
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
 	n.NetworkID = idgen.NextID(0)
 	return errs.DB(db.Network_Insert(a.db, n))
 }
 
 func (a *API) Network_Delete(n *Network) error {
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
+	exists, err := db.Network_HasPeers(a.db, n.NetworkID)
+	if err != nil {
+		return errs.DB(err)
+	}
+	if exists {
+		return errs.Conflict.WithMsg("Delete all peers before deleting network.")
+	}
+
 	return errs.DB(db.Network_Delete(a.db, n.NetworkID))
 }
 
@@ -189,6 +203,9 @@ func (a *API) Network_List() ([]*Network, error) {
 }
 
 func (a *API) Peer_CreateNew(p *Peer) error {
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
 	p.WGPubKey = []byte{}
 	p.SignPubKey = []byte{}
 	p.APIKey = idgen.NewToken()
@@ -217,6 +234,9 @@ func (a *API) Peer_Init(peer *Peer, args m.PeerInitArgs) error {
 }
 
 func (a *API) Peer_Delete(networkID int64, peerIP byte) error {
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
 	return errs.DB(db.Peer_Delete(a.db, networkID, peerIP))
 }
 
diff --git a/hub/api/db/written.go b/hub/api/db/written.go
index 11251f2..da3d4c9 100644
--- a/hub/api/db/written.go
+++ b/hub/api/db/written.go
@@ -1,5 +1,7 @@
 package db
 
+import "database/sql"
+
 func Peer_ListAll(tx TX, networkID int64) ([]*Peer, error) {
 	const query = Peer_SelectQuery + ` WHERE NetworkID=? ORDER BY PeerIP ASC`
 	return Peer_List(tx, query, networkID)
@@ -11,3 +13,9 @@ func Peer_GetByAPIKey(tx TX, apiKey string) (*Peer, error) {
 		Peer_SelectQuery+` WHERE APIKey=?`,
 		apiKey)
 }
+
+func Network_HasPeers(db *sql.DB, networkID int64) (exists bool, err error) {
+	const query = "SELECT EXISTS(SELECT 1 FROM peers WHERE NetworkID=?)"
+	err = db.QueryRow(query, networkID).Scan(&exists)
+	return exists, err
+}
diff --git a/hub/handlers.go b/hub/handlers.go
index 2db9157..1f8c8d9 100644
--- a/hub/handlers.go
+++ b/hub/handlers.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"log"
 	"math/rand/v2"
+	"net"
 	"net/http"
 	"time"
 	"vppn/hub/api"
@@ -28,11 +29,12 @@ func (a *App) _signin(s *api.Session, w http.ResponseWriter, r *http.Request) er
 }
 
 func (a *App) _signinSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	if !a.signInLock.TryLock(r.RemoteAddr) {
+	host, _, _ := net.SplitHostPort(r.RemoteAddr)
+	if !a.signInLock.TryLock(host) {
 		time.Sleep(time.Duration(rand.Int64N(int64(4 * time.Second))))
 		return errs.ErrNotAuthorized
 	}
-	defer a.signInLock.Unlock(r.RemoteAddr)
+	defer a.signInLock.Unlock(host)
 
 	var pwd string
 	err := webutil.NewFormScanner(r.Form).
@@ -244,7 +246,7 @@ func (a *App) _adminPasswordSubmit(s *api.Session, w http.ResponseWriter, r *htt
 		return err
 	}
 
-	if len(newPwd) < 8 {
+	if len(newPwd) < 8 || len(newPwd) > 72 {
 		return errs.ErrInvalidPassword
 	}
 
@@ -342,9 +344,10 @@ func (a *App) peersList(networkID int64) (peers []m.Peer, err error) {
 		}
 		wgKey, err := wgtypes.NewKey(p.WGPubKey)
 		if err != nil {
-			log.Printf("Bad WG key in DB for peer %v", p)
+			log.Printf("Bad WG key in DB for peer %d/%d", p.NetworkID, p.PeerIP)
 			continue // malformed key; skip rather than serve garbage
 		}
+
 		var signKey [32]byte
 		copy(signKey[:], p.SignPubKey)
 		peers = append(peers, m.Peer{
diff --git a/peer/init.go b/peer/init.go
index e3a1699..029a513 100644
--- a/peer/init.go
+++ b/peer/init.go
@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"net/netip"
 	"os"
+	"time"
 
 	"golang.org/x/crypto/nacl/sign"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
@@ -93,7 +94,7 @@ func initFromHub(hubURL, apiKey string, privKey wgtypes.Key) (LocalState, error)
 	req.SetBasicAuth("", apiKey)
 	req.Header.Set("Content-Type", "application/json")
 
-	resp, err := http.DefaultClient.Do(req)
+	resp, err := (&http.Client{Timeout: time.Minute}).Do(req)
 	if err != nil {
 		return LocalState{}, fmt.Errorf("hub init: %w", err)
 	}
diff --git a/peer/multicast/receiver.go b/peer/multicast/receiver.go
index c8d3a10..0ceae23 100644
--- a/peer/multicast/receiver.go
+++ b/peer/multicast/receiver.go
@@ -63,13 +63,14 @@ func receiver(selfVPNIP netip.Addr, limiters []*ratelimiter.Limiter, ch chan<- P
 			continue
 		}
 
-		if err := limiters[packet.PeerIP].Limit(); err != nil {
-			log.Printf("Rate limited packet from peer IP %d.", packet.PeerIP)
+		// Slightly cheaper than limiting.
+		age := time.Since(time.Unix(packet.Timestamp, 0))
+		if age > maxPacketAge || age < -maxPacketAge {
 			continue
 		}
 
-		age := time.Since(time.Unix(packet.Timestamp, 0))
-		if age > maxPacketAge || age < -maxPacketAge {
+		if err := limiters[packet.PeerIP].Limit(); err != nil {
+			log.Printf("Rate limited packet from peer IP %d.", packet.PeerIP)
 			continue
 		}