ICX Brocade switch forwarding LLDP packet

[alex_shalima]

Hello,

I'm working a hybrid-vendor network. Here is how it is all connected:

Cisco 4500 -> Brocade 7450 -> Brocade 7250 -> HP 2920 

Situation:
The funny thing is that on the uplink port of the HP switch (port 24) I'm seeing the Cisco 4500 LLDP info. By standard, it shouldn't really be there. It's 2 hops too far to show that data. 


------------------------------------------------------------------------------
  Local Port   : 24
  ChassisType  : mac-address
  ChassisId    : 78 a6 e1 09 cb 58
  PortType     : mac-address
  PortId       : 78 a6 e1 09 cb 8f
  SysName      : SW-MDF-3-02
  System Descr :
  PortDescr    : 10GigabitEthernet1/2/7
  Pvid         : 7

  System Capabilities Supported  : bridge
  System Capabilities Enabled    : bridge

  Remote Management Address
     Type    : ipv4
     Address : 10.7.254.11

------------------------------------------------------------------------------
  Local Port   : 24
  ChassisType  : local
  ChassisId    : HRH-4500X-VSS
  PortType     : local
  PortId       : TenGigabitEthernet1/16
  SysName      :
  System Descr : Cisco IOS Software, IOS-XE Software, Catalyst 4500 L3 Swi...
  PortDescr    :
  Pvid         :

  System Capabilities Supported  : bridge, router
  System Capabilities Enabled    : bridge, router

  Remote Management Address
     Type    : ipv4
     Address : 172.17.10.1


My question is: does Brocade implement any sort of LLDP packet forward mechanism? If it does, can it be limited to only 1 switch?

[BenBeck]

If LLDP is off on the ICXs, we will likely forward/flood LLDP like any other packet. If LLDP is on (lldp run globally), we will trap it to the cpu and it will not be forwarded. Do you have LLDP on for the two ICXs?

[alex_shalima]

Hi Ben,

Thanks for replying. I have checked both Brocades and LLDP was on. I also have ran "lldp run" command just in case.

"show lldp" from 7250:

SSH@MDF-3-02#show lldp
LLDP transmit interval           : 30 seconds
LLDP transmit hold multiplier    : 4  (transmit TTL: 120 seconds)
LLDP transmit delay              : 2 seconds
LLDP SNMP notification interval  : 5 seconds
LLDP reinitialize delay          : 2 seconds
LLDP-MED fast start repeat count : 3

LLDP maximum neighbors           : 392
LLDP maximum neighbors per port  : 4


What is interesting is that 7250 switch does not show 2 entries like HP does, so it is working like intended, but the HP switches that connect to 7250 do show the Cisco 4500.

[mitchell_axtell]

HP includes the output of "show cdp neighbors" in LLDP, and vice-versa.  That looks like a CDP result, which the ICX switches are likely forwarding as they do not process it.  You could try disabling CDP TX on the 4500's port to confirm.

[BenBeck]

The same concept will apply for cdp as well. If it is off on the ICX, we forward it. If you turn on 'cdp run', we will evaluate incoming cdp and it will be shown in 'show fdp neigh' output.