topic RE: ELRP in ExtremeSwitching (EXOS/Switch Engine)

ELRP

Peder_Bach — Mon, 12 Nov 2018 15:23:00 GMT

I try to find how many ELRP sessions we could have on a Extreme switch, does any have the scaling numbers?

RE: ELRP

Ty_Izzet — Tue, 13 Nov 2018 23:17:00 GMT

You should be able to create as many ELRP sessions as you can VLANs.
There is no limitation on creating the number of sessions in EXOS. However, this may have some impact with traffic so you may want to increase the interval if there are a high number of sessions involved.

X460G2-48p-G4.186 # sh elrp
ELRP Standalone Client: Enabled
ELRP Inter-VLAN loop detection:On

Number of ELRP sessions: 4093
Number of ELRP pkts transmitted: 0
Number of ELRP pkts received: 0

Interval Pkts Pkts Disable
Client VLAN Ports (sec) Count Cyclic Xmit Rcvd Action Port (sec)
----------------------------------------------------------------------------------------------
CLI Default All 1.0 0 Yes 0 0 LT -
CLI VLAN_0002 All 1.0 0 Yes 0 0 LT -
CLI VLAN_0003 All 1.0 0 Yes 0 0 LT -
CLI VLAN_0004 All 1.0 0 Yes 0 0 LT -
CLI VLAN_0005 All 1.0 0 Yes 0 0 LT -
...

RE: ELRP

Roy_Noh — Wed, 14 Nov 2018 09:11:00 GMT

As Taykin mentioned, there's no limitation on creating ELRP sessions.
But be aware that those ELRP packets are CPU generated which means sending out a excessive number of them can cause CPU busy that can cause unexpected behavior.

Let's say you have configured 10 ports as tagged assigned 100 VLANs and ELRP is enabled on all of them.
Then each port need to generate 100 ELRP mcast packets so 1,000 packets total.
If ELRP interval is set to 1 second, ELRP alone generates 1,000 pps which may cause tx congestion.

To avoid this, do not make the ELRP interval too short and add only required ports on the ELRP.