ICMP Echo Reply through trunk in 2 vlans

[robertsmith10]

Hello,

  Can someone please help me with the following situation: 

Having 4 hosts (C1, C2, C3 and C4), C1 and C2 connected to SW1; C3, C4 connected to SW2; C1 and C3 in VLAN1; C2 and C4 in VLAN2.

Both SW1 and SW2 are connected through a trunk port.

If C2 sends ICMP Echo Request to C3, will C2 receive ICMP Echo Reply?

Thank you very much.

[Reza Sharifi]

Hi,

Yes, as long as inter-vlan routing is configured for vlan 1 and 2.

Here is doc for reference:

http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/ios-software-releases-121-mainline/12778-ping-traceroute.html

HTH

[Carlos Villagran · Accepted solution]

Hi!

No. They need a default-gateway which will route the packets to the other subnet. The two switches by itself will not be able to communicate.

This can be achieved with a router or as Reza said, using inter-vlan routing.

Hope it helps, best regards!

JC

[jamiebutterworth2016]

If the switch is layer 2 only, the icmp won't get through because C2 and C3 reside on different vlans.