Known Limitations

Note the following caveats that were disclosed in the NPB 21.1.2.0 release that is applicable for this release of the software as well.

GRE tunnel encapsulation does not support MPLS packets
When an MPLS packet is subjected to GRE encapsulation, the protocol ID in the GRE header is set to 0.
Listener policy byte count is incorrect when truncation is enabled
On Extreme 9920 devices, the byte count for truncated packets is the actual byte count seen by the egress ACL before truncation.
GRE version-1 packets are not filtered with the 'network-id-type:NETWORK_ID_TYPE_GRE' rule
The rule filters the GRE version-0 packets.
Scale limitation of 2000 ingress groups is not achieved in a certain configuration
When both transport tunnels and ingress groups are configured, some of the non-transport ingress groups are not stored in the hardware table. Ingress groups that are not in the hardware table are not counted toward the scale limit.
Filtering by the authentication header is not supported
You cannot configure ACLs for IP ESP (Encapsulating Security Payload) that filter for the authentication header.
MAC ACL counters are incremented when traffic matches IPv4, IPv6, and MAC ACLs
If multiple matches, in different ACL types, are on permit rules, only the match in the highest-preference type is implemented. Lower-preference matches are ignored. The preference order is Layer 3 > Layer 2. The counters are incremented for all the matching ACLs because they indicate that a match is found.
Matching packets based on IGMP group address for both IPv4 and IPv6 is not supported
You cannot configure ACL rules to match packets based on the IGMP group address for both IPv4 and IPv6.
Transport tunnel termination is supported only for ERSPAN Type II
Transport tunnel termination considers only ERSPAN Type II headers for termination and does not consider any specific SPAN-ID to terminate and further classify the flows.
Device links are not operational for 100G LR4 optic with FEC mode set to auto
To enable the links between Extreme 9920, SLX 9140, and SLX 9240 devices to be operational with 100GBASE-LR4 optics, configure one of the following
  • Disable FEC on Extreme 9920 devices.
  • Enable RS-FEC on SLX devices when the peer side FEC configuration is set to auto.
IPv6 packets with extension headers cannot be matched, filtered, or forwarded
On Extreme 9920 devices, IPv6 packets with extension headers cannot be matched, filtered, or forwarded on standard TCP or UDP protocols.
Multiple SNMP linkUp or linkDown traps are generated during SNMP upgrade
This situation occurs when you upgrade the SNMP service with the system service update command. These traps do not impact functionality and there is nothing you need to do.
Overwriting of mirror sessions and packet capture due to ASIC behavior
A mirror session programmed at one stage will be overwritten by a subsequent stage if the packet matches an entry in the table. Onboard PCAP capture of ACL will overwrite packet capture of ingress interface and tunnel based captures.
100G-DR, FR optical transmission
The 100G-DR, FR uses a single laser and operates with PAM4 modulation at 53.125 Gb on the optical side. Since PAM4 encodes 2 bits per symbol, this results in a 100G transmission rate. Channels 2, 3, and 4 should remain inactive, so the tx, rx, and txbias data will show proper values for channel 1, and either infinity or 0.00 for channels 2, 3, and 4.
9039087-00 Rev AA