/BUILT-IN

Well-Known Intervals

Default timers across Cisco IOS, IOS-XE, NX-OS, JunOS, and Unified WLAN. The lookup for figuring out which protocol owns that suspicious flapping cadence.

v1 · 2026.05.26

Default timer values across Cisco IOS, IOS-XE, NX-OS, JunOS, and Unified WLAN platforms. The companion to “Well-Known Intervals” — when something’s flapping or pinging on a suspicious cadence, this is the lookup table to figure out which protocol owns it.

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Defaults vary by platform and software version. Treat this as a starting point and verify against your specific code train (especially for BFD, OSPF throttle, NAT timeouts, and anything Junos vs. IOS-XE). Original list compiled by Jeremy Stretch on the old PacketLife wiki, reposted with permission, expanded since.

Sub-10 seconds

Hello timers, keepalives, EAP, IGMP, BFD — anything that ticks fast.

150ms Default BFD minimum interval (Cisco IOS-XE). Detection time = 150ms × 3 multiplier = 450ms.
1s Default VRRP hello timer.
1s Default BFD minimum interval (Junos). Detection time = 1s × 3 = 3s.
1s LACP fast-rate hello PDU interval (when configured).
1s IPv6 ND DAD (Duplicate Address Detection) probe interval.
1s IPv6 ND retransmit timer.
1s Default EAP-Identity-Request timeout (Unified WLAN).
1s Default EAP-Request timeout (Unified WLAN).
1s Default EAPOL-KEY timeout (Unified WLAN).
1s CleanAir AP sampling interval (Unified WLAN).
1s Default IGMPv2 group-specific query interval (max response time of 10).
2s Default IEEE 802.1D STP hello timer.
2s Default RADIUS / LDAP server timeout (Unified & Autonomous WLAN).
2s Default NMSP updates from WLC to Loc/MSE server (Unified WLAN).
2s Default IGMPv2 last-member query count × 2.
3s Default GLBP hello timer (Cisco IOS).
3s Default HSRP hello timer (Cisco IOS).
3s LACP fast-rate timeout (3 × fast-rate hello).
5s Default EIGRP hello timer on links ≥ 1.544 Mbps (Cisco IOS).
5s Default LDP hello timer for links (Cisco IOS).
5s Default TACACS+ / RADIUS server response timeout.
5s Default OSPF SPF throttle initial delay (5000ms, Cisco IOS-XE).
10s Default HSRP hold timer (Cisco IOS).
10s Default IS-IS hello timer (Cisco IOS).
10s Default OSPF hello on broadcast & point-to-point links (Cisco IOS / JunOS).
10s Default 802.1x supplicant response timeout (Unified WLAN).
10s Default Mobility keepalive interval (Unified WLAN).
10s Default AP discovery timeout (Unified WLAN).
10s Default LDP hello timer for targeted LDP (Cisco IOS).
10s Default LMI Frame Relay message.
10s Default IGMPv2 query response interval.
10s Default GRE keepalive interval (when enabled; off by default).
10s Default OSPF SPF throttle hold (10000ms, Cisco IOS-XE).

10 seconds to 1 minute

STP, UDLD, LLDP, RIP, the slower hellos.

15s Default EIGRP hold timer on links ≥ 1.544 Mbps (Cisco IOS).
15s Default IEEE 802.1D STP forwarding delay.
15s Default UDLD probe interval (Cisco IOS).
15s CleanAir AP AQI calculation interval (Unified WLAN).
15s Default LDP hold timer for link hellos (Cisco IOS).
15s Default LDP hello timer for targeted LDP (JunOS).
20s Default IEEE 802.1D STP maximum BPDU age.
20s WCP keep-alive timer (Unified WLAN WiSM / Cat65k / 3750).
30s Default IS-IS hold timer (Cisco IOS).
30s Default LLDP advertisement interval (Cisco IOS).
30s Default OSPF hello on nonbroadcast links (Cisco IOS).
30s Default RIP update interval.
30s Default AP heartbeat timeout (Unified WLAN).
30s Default 802.1x supplicant response timeout (Autonomous WLAN).
30s Default DTP hello interval (Cisco IOS).
30s Default PIM hello timer.
30s Default IPv6 ND reachable time.
30s LACP slow-rate hello PDU interval (default).
64s Default NTP poll minimum (2^6 seconds).
40s Default OSPF hold timer on broadcast & point-to-point links (Cisco IOS / JunOS).
45s Default LDP hold timer for targeted hellos (JunOS).
60s Default BGP keepalive interval.
60s Default BGP scan time for next-hop validation (Cisco IOS).
60s Default CDP advertisement interval (Cisco IOS).
60s Default EIGRP hello on links < 1.544 Mbps (Cisco IOS).
60s Default NAT DNS translation timeout (Cisco IOS).
60s Default NAT ICMP translation timeout (Cisco IOS).
60s Default NAT TCP SYN packet translation timeout (Cisco IOS).
60s Default NAT TCP FIN/RST packet translation timeout (Cisco IOS).
60s Default RRM neighbor packets (Unified WLAN).
60s Default CCX location measurement (Unified WLAN).
60s Default client exclusion (Unified WLAN).
60s Default IGMP snooping timeout (Unified WLAN).
60s Default client idle timeout (Autonomous WLAN).
60s Default LMI Frame Relay full status message (every 6th message).

1 to 5 minutes

Hold timers, IGMPv2 lifetimes, NAT translations, errdisable recovery.

90s Traffic stream metric reports (Unified WLAN).
90s Default LDP hold timer for targeted hellos (Cisco IOS).
90s LACP slow-rate timeout (3 × 30s slow hello).
90s Default MSDP SA refresh advertisement timer.
105s Default PIM hold timer (3.5 × 30s hello).
120s Default BGP Graceful Restart restart timer.
120s Default OSPF hello on nonbroadcast links (JunOS).
120s Default OSPF hold timer on nonbroadcast links (Cisco IOS).
120s Default AP primary discovery timeout (Unified WLAN).
125s Default IGMPv2 query interval.
200s Default IPv6 ND Router Advertisement minimum interval.
180s Default BGP hold timer.
180s Default EIGRP hold timer on links < 1.544 Mbps (Cisco IOS).
180s Default RIP holddown timer.
180s Default RIP invalidation timer.
180s EIGRP SIA.
180s Default RRM off-channel scanning sweep time (Unified WLAN).
240s Default RIP flush timer.
255s Default IGMPv2 other-querier-present interval.
260s Default IGMPv2 group membership interval.
300s Default DHCP snooping database transfer timeout (Cisco IOS).
300s Default NAT UDP translation timeout (Cisco IOS).
300s Default recovery period for many errdisable triggers (Cisco IOS).
300s Default MAC address table aging time (Cisco IOS).
300s Default TCP session timer (F5 BIG-IP).
300s Default client idle timeout (Unified WLAN).
300s Default ARP timeout (Unified WLAN).
300s Default RADIUS fallback interval (Unified WLAN).

5 minutes to 1 hour

WLAN housekeeping, OSPF LSA refresh, NHRP, IGMP leave, NTP poll max.

5m 20s WCP keep-alive timeout & controller reboot (Unified WLAN WiSM / Cat65k / 3750).
6m Default BGP Graceful Restart stale-path timer (360s).
10m Default IPv6 ND Router Advertisement maximum interval (600s).
17m Default NTP poll maximum (2^10 = 1024 seconds).
30m Default NHRP holdtime (DMVPN, 1800s).
10m Default VTY exec-timeout (Cisco IOS).
10m Default GLBP redirect timer.
10m Default RF group update interval (Unified WLAN).
10m Default RRM DCA channel update interval (Unified WLAN).
10m Default RRM TPC power update interval (Unified WLAN).
15m CleanAir AQI reporting interval (Unified WLAN).
16m 40s Default IGMP leave timer (Cisco IOS).
20m Default rogue entry timeout (Unified WLAN).
30m OSPF LSA refresh timer.
30m Default client session timeout (Unified WLAN).

1 hour and longer

ARP, NAT TCP, OSPF LSA expiration, TCP keepalive, the long-running stuff.

1h OSPF LSA expiration timer.
1h Default 802.1X reauthentication timer (3600s, when reauth is enabled).
1h Default DHCPv6 SOL_MAX_RT (max solicit retransmission interval, 3600s).
2h Default TCP keepalive timer / interval.
4h Default ARP timeout (Cisco IOS).
4h Default GLBP timeout timer.
24h Default NAT TCP translation timeout (Cisco IOS).
24h Default WLC local guest user account lifetime (Unified WLAN).
7d CleanAir persistent device avoidance interval (Unified WLAN).

EOF · git 2.x · gh 2.x · companion to Git for Network Engineers series rendered · routerjockey.com/tools/well-known-intervals · 2026.05.26