Symptom

IPv6 link local BGP classification on CoPP missing on GX/GX2 PIDs. LLA IPv6 addressing is defined as an address within prefix FE80::/10. Support for this on CloudScale requires the TCAM carving to be increased for the Ingress SUP region from 512 to 768 in order to provide more space for CoPP to add this match under the critical class. However, even after the increase in TCAM is performed on the Ingress SUP, IPv6 LLA BGP packets remain classified under the default class. This can lead to drops and corresponding TCP retransmission (latency) in deployments: C9316D-GX# sh bgp ipv6 uni sum BGP summary information for VRF default, address family IPv6 Unicast BGP router identifier 2.2.2.2, local AS number 65000 BGP table version is 2, IPv6 Unicast config peers 1, capable peers 1 0 network entries and 0 paths using 0 bytes of memory BGP attribute entries [0/0], BGP AS path entries [0/0] BGP community entries [0/0], BGP clusterlist entries [0/0] Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd fe80::100:1 4 65000 12 12 2 0 0 00:06:34 0 C9316D-GX# sh policy-map interface control-plane | sec class-default ; sh policy-map interface control-plane | sec critical tem inte class-map class-default (match-any) set cos 0 police cir 400 kbps , bc 32000 bytes module 1 : transmitted 2563 bytes; 5-minute offered rate 11 bytes/sec conformed 11 peak-rate bytes/sec at Thu Oct 07 03:05:06 2021 class-map copp-system-p-class-critical (match-any) match access-group name copp-system-p-acl-bgp match access-group name copp-system-p-acl-rip match access-group name copp-system-p-acl-vpc match access-group name copp-system-p-acl-bgp6 match access-group name copp-system-p-acl-ospf match access-group name copp-system-p-acl-rip6 match access-group name copp-system-p-acl-eigrp match access-group name copp-system-p-acl-ospf6 match access-group name copp-system-p-acl-eigrp6 match access-group name copp-system-p-acl-auto-rp match access-group name copp-system-p-acl-mac-l3-isis set cos 7 police cir 36000 kbps , bc 1280000 bytes module 1 : transmitted 0 bytes; 5-minute offered rate 0 bytes/sec conformed 0 peak-rate bytes/sec C9316D-GX-02# sh system internal access-list sup-redirect-stats | i i bgp|link 2871 copp-system-p-acl-bgp 0 0 2874 copp-system-p-acl-bgp 0 0 2875 copp-system-p-acl-bgp 0 0 2880 copp-system-p-acl-bgp 0 0 3003 IPV4 Link Local Mcast 0 0 3172 IPV6 ND Link Local REDIRECT 0 0 3186 IPV6 Link Local Ucast 0 0 3188 IPV6 Link Local Mcast 0 0 2871 copp-system-p-acl-bgp 0 0 2874 copp-system-p-acl-bgp 0 0 2875 copp-system-p-acl-bgp 0 0 2880 copp-system-p-acl-bgp 0 0 3003 IPV4 Link Local Mcast 0 0 3172 IPV6 ND Link Local REDIRECT 0 0 3186 IPV6 Link Local Ucast 19 2014 * 3188 IPV6 Link Local Mcast 0 0 2871 copp-system-p-acl-bgp 0 0 2874 copp-system-p-acl-bgp 0 0 2875 copp-system-p-acl-bgp 0 0 2880 copp-system-p-acl-bgp 0 0 3003 IPV4 Link Local Mcast 0 0 3172 IPV6 ND Link Local REDIRECT 0 0 3186 IPV6 Link Local Ucast 0 0 3188 IPV6 Link Local Mcast 0 0 2871 copp-system-p-acl-bgp 0 0 2874 copp-system-p-acl-bgp 0 0 2875 copp-system-p-acl-bgp 0 0 2880 copp-system-p-acl-bgp 0 0 3003 IPV4 Link Local Mcast 0 0 3172 IPV6 ND Link Local REDIRECT 0 0 3186 IPV6 Link Local Ucast 0 0 3188 IPV6 Link Local Mcast 0 0

Conditions

Nexus 9000 GX/GX2 Series Running 9.3(x) or 10.x This includes 10.2(1q).

Workaround

There is no workaround for this.

Further Problem Description