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High latency on newly created VLAN


Hey guys, I'm running a pair of Cisco Nexus 9K's in HSRP mode as the core routers. I created a a subnet to accomodate our ever-increasing list of BOYD devices. I noticed that the latency is extremely high when pinging clients in this subnet:

64 bytes from icmp_seq=6627 ttl=63 time=424.914 ms
64 bytes from icmp_seq=6628 ttl=63 time=289.047 ms
64 bytes from icmp_seq=6629 ttl=63 time=219.505 ms
64 bytes from icmp_seq=6630 ttl=63 time=396.309 ms
64 bytes from icmp_seq=6631 ttl=63 time=251.964 ms
64 bytes from icmp_seq=6632 ttl=63 time=379.557 ms
64 bytes from icmp_seq=6633 ttl=63 time=549.037 ms
64 bytes from icmp_seq=6634 ttl=63 time=436.171 ms
64 bytes from icmp_seq=6635 ttl=63 time=635.576 ms
64 bytes from icmp_seq=6636 ttl=63 time=470.314 ms
64 bytes from icmp_seq=6637 ttl=63 time=390.080 ms
64 bytes from icmp_seq=6638 ttl=63 time=304.494 ms
64 bytes from icmp_seq=6639 ttl=63 time=478.791 ms
64 bytes from icmp_seq=6640 ttl=63 time=556.774 ms
64 bytes from icmp_seq=6641 ttl=63 time=469.451 ms
64 bytes from icmp_seq=6642 ttl=63 time=1564.194 ms

64 bytes from icmp_seq=6643 ttl=63 time=559.249 ms
64 bytes from icmp_seq=6644 ttl=63 time=423.030 ms

I took a PCAP and discovered there are tons of arp requests from devices asking who the default gateway is (ex: Who has Tell It looks like the mac address of the default gateway is not being resolved. Could this be the culprit to our latency issue? I am able to ping but this address only shows as active in the arp table on the standby router for some reason. 

Address Age MAC Address Interface Flags 00:07:48 0000.0c9f.f320 Vlan800

Here is our VLAN configuration. The standby router looks identical for the most part with the exception of the interface IP and HSRP priority (, priority 125). Any help would be much appreciated. Thanks in advance! 

IP Interface Status for VRF "default"(1)
Vlan800, Interface status: protocol-up/link-up/admin-up, iod: 139,
IP address:, IP subnet: route-preference: 0, tag: 0
IP broadcast address:
IP multicast groups locally joined:
IP MTU: 1500 bytes (using link MTU)
IP primary address route-preference: 0, tag: 0
IP proxy ARP : disabled
IP Local Proxy ARP : disabled
IP multicast routing: disabled
IP icmp redirects: disabled
IP directed-broadcast: disabled
IP Forwarding: disabled
IP icmp unreachables (except port): disabled
IP icmp port-unreachable: enabled
IP unicast reverse path forwarding: none
IP load sharing: none
IP interface statistics last reset: never
IP interface software stats: (sent/received/forwarded/originated/consumed)
Unicast packets : 62804/155833/646/62238/359075
Unicast bytes : 42174958/68353903/187096/41994582/159289835
Multicast packets : 1/2149160/0/1/753830
Multicast bytes : 82/369070078/0/82/30153200
Broadcast packets : 0/0/0/0/0
Broadcast bytes : 0/0/0/0/0
Labeled packets : 0/0/0/0/0
Labeled bytes : 0/0/0/0/0
WCCP Redirect outbound: disabled
WCCP Redirect inbound: disabled
WCCP Redirect exclude: disabled
Vlan800 - Group 800 (HSRP-V2) (IPv4)
Local state is Active, priority 150 (Cfged 150), may preempt
Forwarding threshold(for vPC), lower: 0 upper: 150
Hellotime 3 sec, holdtime 10 sec
Next hello sent in 1.556000 sec(s)
Virtual IP address is (Cfged)
Active router is local
Standby router is , priority 125 expires in 7.817000 sec(s)
Authentication text "cisco"
Virtual mac address is 0000.0c9f.f320 (Default MAC)
8 state changes, last state change 1w0d
IP redundancy name is hsrp-Vlan800-800 (default)
interface Vlan800
no shutdown
no ip redirects
ip address
ip ospf passive-interface
ip router ospf 100 area
hsrp version 2
hsrp 800
priority 150
ip dhcp relay address
ip dhcp relay address


1 Reply 1

VIP Alumni
VIP Alumni

It's interesting that the primary HSRP interface does not show any broadcasts in the counters. It appears it is not seeing the ARP requests or any broadcasts are not reaching it or are blocked. You may have a topology or spanning tree type issue. Take a close look at the root bridges for the VLAN, what interfaces are blocking and that the VLAN is properly allowed on the necessary interfaces. A good start anyway.

Hope this helps.


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