diff --git a/deploy/ha/README.md b/deploy/ha/README.md
index fa679a6..1e2d531 100644
--- a/deploy/ha/README.md
+++ b/deploy/ha/README.md
@@ -1,4 +1,4 @@
-# Two control planes
+# More than one control plane
 
 llmgw handles the hard half of this itself: only one control plane places work,
 and agents find whichever one is leading. What it does not do is move client
@@ -37,7 +37,7 @@ nothing in front of the two had moved.
 So something has to. The options, in the order most people should consider
 them:
 
-**A load balancer you already run.** Health-check `/ready` on each control
+**A load balancer you already run.** Health-check `/leader` on each control
 plane and send traffic to whichever answers. This is the right answer if you
 have one, and it needs nothing else from this directory.
 
@@ -50,25 +50,50 @@ in whatever your resolvers actually honour rather than what you set, which on
 a bad day is minutes. Fine for a cluster people use interactively, wrong for
 one an agent is driving.
 
-## Check `/ready`, not `/health`
+## Check `/leader`, not `/health`
 
 This is the one thing to get right, and the obvious choice is the wrong one.
 
-`/health` says the process is up. It says nothing about whether it can serve,
+`/health` says the process is up. It says nothing about whether it leads,
 and a standby is exactly that case: alive, answering, and holding no endpoints
 at all — its reconciler placed nothing and it has no agent streams to adopt
-from. A load balancer checking `/health` would send it half the traffic, and
-half the traffic would be a 503.
+from. A standby passes client requests on to the leader, so traffic sent to
+one still works — until the leader is the machine that was lost, and there
+is nobody to pass them to.
+
+`/leader` is 200 on the control plane that leads and 503 on a standby. It is
+what keepalived follows for the floating address, and what a load balancer
+should send traffic by: to the one machine that answers 200.
+
+`/ready` is narrower: 200 only when this process has somewhere to send a
+request, so 503 on a standby and also on a leader with no model running yet.
+Checking it takes the portal and the admin pages away with the models — on a
+new cluster with no node yet, nobody can sign in to add one. Use it to stop
+sending inference only, if your load balancer can tell the paths apart.
 
-`/ready` says this process has somewhere to send a request. It is 503 on a
-standby, 503 on a leader whose replicas have all failed, and 200 when there is
-something to serve — which is the question a load balancer is actually asking.
 Both are open, because a load balancer has no key.
 
-During a failover neither passes for about the length of the lease handover:
+During a failover nothing passes for about the length of the lease handover:
 three seconds when the leader is stopped cleanly, up to the lease TTL when it
-is not. That gap is real and there is no way to have it both ways — traffic
-cannot go to a control plane that has nothing to route to.
+is not. A proxy that waits that long for a healthy machine rather than
+failing at once (Caddy's `lb_try_duration`) hides it from clients.
+
+**Caddy**, in front of three control planes — the end of
+[deploy/proxy/Caddyfile](../proxy/Caddyfile) has it with the rest of the
+settings:
+
+```
+reverse_proxy 10.0.0.157:8080 10.0.0.158:8080 10.0.0.159:8080 {
+	lb_policy first
+	health_uri /leader
+	health_interval 2s
+	lb_try_duration 15s
+	flush_interval -1
+}
+```
+
+With a floating address the address already follows the leader: give Caddy
+that one address instead.
 
 Not the admin port, for a different reason: it serves pprof, and pprof can
 dump the process heap, where API keys sit in plaintext.
diff --git a/deploy/ha/keepalived.conf.example b/deploy/ha/keepalived.conf.example
index c728d40..5921fae 100644
--- a/deploy/ha/keepalived.conf.example
+++ b/deploy/ha/keepalived.conf.example
@@ -41,7 +41,9 @@ vrrp_instance llmgw {
     # MASTER on the machine you would rather serve; BACKUP on the other.
     state MASTER
     interface eth0
-    # Any number both machines agree on and nothing else on the segment uses.
+    # Any number both machines agree on and nothing else on the segment uses:
+    # another cluster's keepalived with the same one reads as an invalid
+    # password. `llmgw server add --vip` derives one from the address.
     virtual_router_id 51
     # The higher one wins while both are healthy. The weight above is enough
     # to invert this when the preferred machine's gateway is not answering.
diff --git a/deploy/proxy/Caddyfile b/deploy/proxy/Caddyfile
index a27034e..5bc8bae 100644
--- a/deploy/proxy/Caddyfile
+++ b/deploy/proxy/Caddyfile
@@ -14,6 +14,7 @@ llm.example.com {
 		max_size 32MB
 	}
 
+	# One control plane. With more than one, see the end of this file.
 	reverse_proxy 127.0.0.1:8080 {
 		# Tokens are written the moment they are generated. Without this a
 		# streamed reply can arrive in bursts, and a client measuring time to
@@ -39,3 +40,36 @@ llm.example.com {
 	# Access log to stderr, which under systemd is the journal.
 	log
 }
+
+# More than one control plane (server init --standbys, server add): one of
+# them leads, the others stand by. Name them all and send to the one that
+# leads — /leader is 200 there and 503 on a standby. Not /ready: that is 503
+# on a leader with no model running yet, and would take the portal away with
+# it. A standby would pass a request on to the leader anyway, but not while
+# there is none, and the hop is for nothing.
+#
+# With a floating address (--vip) the address already follows the leader:
+# give reverse_proxy that one address instead, and keep the rest as above.
+#
+# llm.example.com {
+# 	request_body {
+# 		max_size 32MB
+# 	}
+# 	reverse_proxy 10.0.0.157:8080 10.0.0.158:8080 10.0.0.159:8080 {
+# 		# The first that is healthy: the leader, whichever it is.
+# 		lb_policy first
+# 		health_uri /leader
+# 		health_interval 2s
+# 		health_timeout 2s
+# 		# While leadership moves — a few seconds when a leader is lost —
+# 		# none is healthy; a request waits that long for one rather than
+# 		# failing at once.
+# 		lb_try_duration 15s
+# 		lb_try_interval 250ms
+# 		flush_interval -1
+# 		transport http {
+# 			response_header_timeout 15m
+# 		}
+# 	}
+# 	log
+# }
diff --git a/docs/install.md b/docs/install.md
index f7963a2..fa33a57 100644
--- a/docs/install.md
+++ b/docs/install.md
@@ -2394,8 +2394,12 @@ and lets it into the store; it starts there as a standby. Every node is told
 of it within half a minute and fails over to it without being touched.
 `--vip` keeps a floating address on whichever control plane leads, with
 keepalived on both: that is the address to give clients, or a proxy in front.
-Without it, put a load balancer in front that checks `/ready` — not
-`/health`, which is 200 on a standby that would refuse every request.
+Without it, put a proxy in front that sends to whichever answers `/leader`
+with 200 — not `/health`, which is 200 on a standby too, and not `/ready`,
+which is 503 on a leader with no model yet and would take the portal away
+with it. The end of [deploy/proxy/Caddyfile](../deploy/proxy/Caddyfile) has
+Caddy doing that for three control planes, and
+[deploy/ha/](../deploy/ha/README.md#check-leader-not-health) why.
 
 - **What a failover costs.** Measured on the reference cluster, stopping the
   leader: the standby led within five seconds, every node had moved to it
diff --git a/internal/cli/serveradd.go b/internal/cli/serveradd.go
index bc1f0bd..9b27bef 100644
--- a/internal/cli/serveradd.go
+++ b/internal/cli/serveradd.go
@@ -9,6 +9,7 @@ import (
 	"encoding/pem"
 	"errors"
 	"fmt"
+	"hash/fnv"
 	"io"
 	"net"
 	"os"
@@ -527,13 +528,22 @@ func (sa *serverAdd) floating(ctx context.Context) error {
 		name     string
 		priority int
 	}{{here, "this machine", 110}, {sa.remote, sa.name, priority}} {
+		// The interface on the address's network, by its route: not the
+		// route to the address, which is lo on the machine holding it
+		// already, as a run after the first finds it.
 		out, err := m.r.Run(ctx, fmt.Sprintf(`set -e
 command -v keepalived >/dev/null 2>&1 || { sudo DEBIAN_FRONTEND=noninteractive apt-get -qq update >/dev/null; sudo DEBIAN_FRONTEND=noninteractive apt-get -qq install -y keepalived >/dev/null; }
-ip -o route get %s | awk '{for(i=1;i<=NF;i++) if($i=="dev") {print $(i+1); exit}}'`, vip), nil)
+dev() { awk '{for(i=1;i<=NF;i++) if($i=="dev") {print $(i+1); exit}}'; }
+d=$(ip -o -4 route show %s | dev)
+[ -n "$d" ] && [ "$d" != lo ] || d=$(ip -o route get %s | dev)
+echo "$d"`, nw.String(), vip), nil)
 		if err != nil {
 			return fmt.Errorf("on %s: %v: %s", m.name, err, strings.TrimSpace(string(out)))
 		}
 		iface := strings.TrimSpace(string(out))
+		if iface == "" || iface == "lo" {
+			return fmt.Errorf("on %s: no interface on %s's network", m.name, sa.vip)
+		}
 		conf := keepalivedConf(iface, vip.String(), prefix, m.priority, pass)
 		if out, err := m.r.Run(ctx, `set -e
 sudo install -d -m 0755 /etc/keepalived
@@ -571,6 +581,17 @@ func vrrpPassword(etcDir string) (string, error) {
 	return pass, nil
 }
 
+// vrrpRouterID is the VRRP router id for a floating address: from the
+// address, so two clusters on one network, each with its own address, do
+// not answer each other's adverts — with one id for all, each logged the
+// other's as an invalid password, and dropped its own address's
+// announcements with them.
+func vrrpRouterID(vip string) int {
+	h := fnv.New32a()
+	_, _ = h.Write([]byte(vip))
+	return int(h.Sum32()%255) + 1
+}
+
 func keepalivedConf(iface, vip string, prefix, priority int, pass string) string {
 	return fmt.Sprintf(`# llmgw: the gateway's floating address, on whichever control plane leads.
 vrrp_script llmgw_leader {
@@ -583,7 +604,7 @@ vrrp_script llmgw_leader {
 vrrp_instance llmgw {
   state BACKUP
   interface %s
-  virtual_router_id 51
+  virtual_router_id %d
   priority %d
   advert_int 1
   authentication {
@@ -597,7 +618,7 @@ vrrp_instance llmgw {
     llmgw_leader
   }
 }
-`, iface, priority, pass, vip, prefix)
+`, iface, vrrpRouterID(vip), priority, pass, vip, prefix)
 }
 
 // clientCapable says a control plane's certificate can also present itself
diff --git a/internal/cli/serverinit_choices_test.go b/internal/cli/serverinit_choices_test.go
index e0a3ba4..6407ef3 100644
--- a/internal/cli/serverinit_choices_test.go
+++ b/internal/cli/serverinit_choices_test.go
@@ -166,3 +166,14 @@ func TestStandbysWantTheStoresMachines(t *testing.T) {
 		t.Errorf("standbys with nowhere to go: %v", err)
 	}
 }
+
+func TestTwoClustersOnOneNetworkKeepApartFloatingAddresses(t *testing.T) {
+	a, b := vrrpRouterID("10.0.0.161"), vrrpRouterID("10.0.0.164")
+	if a == b || a < 1 || a > 255 || b < 1 || b > 255 {
+		t.Errorf("router ids %d and %d", a, b)
+	}
+	conf := keepalivedConf("ens18", "10.0.0.164", 24, 100, "secret12")
+	if !strings.Contains(conf, fmt.Sprintf("virtual_router_id %d\n", b)) || !strings.Contains(conf, "interface ens18") {
+		t.Errorf("conf:\n%s", conf)
+	}
+}
diff --git a/internal/cli/tui_choices.go b/internal/cli/tui_choices.go
index dcfe560..a520aaa 100644
--- a/internal/cli/tui_choices.go
+++ b/internal/cli/tui_choices.go
@@ -257,7 +257,7 @@ func newInstallForm(in *serverInit, host string, found []string, ha bool) *insta
 		},
 	}
 	if ha {
-		f.starter.about += " With three machines it runs on the first node that has room for it."
+		f.starter.about += " Unless this machine is a node, it runs on the first node that joins with room for it."
 	}
 
 	// --- pictures and 3D ---
diff --git a/internal/cli/tui_setup.go b/internal/cli/tui_setup.go
index 6ddc93d..976de62 100644
--- a/internal/cli/tui_setup.go
+++ b/internal/cli/tui_setup.go
@@ -112,6 +112,10 @@ func newDBMachine(n int) dbMachine {
 	if os.Getenv("SSH_AUTH_SOCK") == "" {
 		m.auth = authKey
 	}
+	// As choosing the way to log in sets them: a key file's path is not a
+	// secret to hide.
+	m.secret.Mask = m.auth == authPassword
+	m.secret.Placeholder = map[int]string{authKey: "/root/.ssh/id_ed25519", authPassword: "the user's ssh password"}[m.auth]
 	return m
 }
 
diff --git a/internal/web/proxy/Caddyfile b/internal/web/proxy/Caddyfile
index a27034e..5bc8bae 100644
--- a/internal/web/proxy/Caddyfile
+++ b/internal/web/proxy/Caddyfile
@@ -14,6 +14,7 @@ llm.example.com {
 		max_size 32MB
 	}
 
+	# One control plane. With more than one, see the end of this file.
 	reverse_proxy 127.0.0.1:8080 {
 		# Tokens are written the moment they are generated. Without this a
 		# streamed reply can arrive in bursts, and a client measuring time to
@@ -39,3 +40,36 @@ llm.example.com {
 	# Access log to stderr, which under systemd is the journal.
 	log
 }
+
+# More than one control plane (server init --standbys, server add): one of
+# them leads, the others stand by. Name them all and send to the one that
+# leads — /leader is 200 there and 503 on a standby. Not /ready: that is 503
+# on a leader with no model running yet, and would take the portal away with
+# it. A standby would pass a request on to the leader anyway, but not while
+# there is none, and the hop is for nothing.
+#
+# With a floating address (--vip) the address already follows the leader:
+# give reverse_proxy that one address instead, and keep the rest as above.
+#
+# llm.example.com {
+# 	request_body {
+# 		max_size 32MB
+# 	}
+# 	reverse_proxy 10.0.0.157:8080 10.0.0.158:8080 10.0.0.159:8080 {
+# 		# The first that is healthy: the leader, whichever it is.
+# 		lb_policy first
+# 		health_uri /leader
+# 		health_interval 2s
+# 		health_timeout 2s
+# 		# While leadership moves — a few seconds when a leader is lost —
+# 		# none is healthy; a request waits that long for one rather than
+# 		# failing at once.
+# 		lb_try_duration 15s
+# 		lb_try_interval 250ms
+# 		flush_interval -1
+# 		transport http {
+# 			response_header_timeout 15m
+# 		}
+# 	}
+# 	log
+# }