A5500 Vlan Interface Latency Spikes

[ccavanna]

Hello -

I was wondering if anyone had any input on this. I am currently testing a pair of A5500G EI (JD377A) switches. I currently have 2 Vlan's configured on them. If I ping the vlan interface ip I see random spike's from 2ms all the way up to 80ms. I currently only have 2 machines plugged into the switches for testing with intervlan routing. Everything else seems to be working correctly but I was wondering if anyone has seen this issue and what the fix was for it. Any insight is appreciated.

Switch 1

Vlan 5

protocol-vlan ipv4

ip-subnet-vlan ip 10.5.1.0 255.255.255.0

Vlan 10

protocol-vlan ipv4

ip-subnet-vlan ip 10.10.1.0 255.255.255.0

Int Vlan 5

Ip address 10.5.1.254 255.255.255.0

Int vlan 10

ip address 10.10.1.254 255.255.255.0

int g1/0/1

port link-mode bridge

port access vlan 10

int g1/0/24

port link-mode bridge

port link-type trunk

port trunk permit vlan 1 5 10

Switch 2

vlan5

No settings

vlan 10

no settings

int vlan 5

no settings

int vlan 10

no settings

int g2/0/1

port link-mode bridge

port access vlan 5

int g2/0/24

port link-mode bridge

port link-type trunk

port trunk permit vlan 1 5 10

[manuel.bitzi · Accepted solution]

Hi ccavanna

Thats usual. pinging a vlan-interface is not reliable, because it is processed be the cpu and answering a icmp request has the lowest priority. It will be also the first packet to be dropped.

If you want test latency, ping a device behind the switch (i.e. a client or server).

BTW: you use a strange configuration. never seen that before

br

Manuel

[ccavanna]

I am sure it is a strange configuration... I am new to vlaning so i am trying to get this figured out. These are going to be a pair of iscsi storage switches stacked via irf (once I get the correct modules). I ordered the AIS and ASE books to get a better grasp on things they will be in my hands today. Thanks for the reply.

[paulgear]

If you're new to VLANs & stuff, i would suggest not using protocol-based VLANs like you have in your current configuration.  Stick with static access or trunk ports and then you know exactly which port is in which VLAN(s) at all times.

As Manuel mentioned, pinging the switch's interface isn't a reliable indicator (much as i wish that it would be).  I've seen up to 20% packet loss to the switch's VLAN interfaces even under light traffic load.