MSS value on ACE SM

[axfalk1]

Hi,

We're running ACE SM A5(3.1a) and were wondering if there's a command that would show the MSS value on the ACE?

Thanks.

[Kanwaljeet Singh · Accepted solution]

Hi,

If you have not configured connection parameter map and set it to some other value then it should be default which if i am not wrong(can be double checked from user guide) is 1460.

For a particular connection you can  use a command:(not pasting full output)

show np X me-stats "-c <conn-id> -vvv"

NP number and connection detail can be obtained using "show connection" output.

ACE30-1/Admin# sh np 1 me-stats  "-c 633710 -vvv"
Connection ID:seq: 633710[0x9ab6e].2
  Other ConnID    : 643599[0x9d20f].2
  Proxy ConnID    : 0[0x0].0
  Next Q    : 0[0x0]

20.20.20.1:21910 -> 20.20.20.2:2000 [RX-NextHop: TX] [TX-NextHop: CP]
  Flags:  PAT: No  DynNAT: No  Implicit PAT: No On_Reuse: No
  L3 Protocol     : IPv4                L4 Protocol    : 6
  Inbound Flag    : 1
  Interface Match : Yes
    Interface MatchID: 8
  EncapsID:ver    : 1:0         TCP ACK delta  : 0x0
  MSS             : 1460                TOS Stamp       : 224
  Repeat mode     : No          Punt Flag      : No

This shall show you the both front end as well as backend leg of the connection.

You need to worry about MSS when ACE is doing L7 loadbalancing.

Regards,

Kanwal

Note: Please mark answers if they are helpful.

[axfalk1]

thanks for your response.

What specifically would we need to worry about MSS when ACE is doing L7 loadbalancing?

Thanks again.

[Kanwaljeet Singh]

Hi,

well not worry but it is seen that when front end and back end MSS in case of L7 LB is not same, performance issues show up. And it is recommended as well.

Regards,

Kanwal

Note: Please mark answers if they are helpful.