Transit vlan

[opnineopnine]

Hi all,

How can I identify a transit vlan?

thanks all.

[Joseph W. Doherty]

Logically or physically or both?

[opnineopnine]

For logically. Thanks.

[Joseph W. Doherty]

Logically a transit VLAN is one carrying traffic that neither is neither sourced or destined for hosts on that VLAN.  I.e. the VLAN carries traffic that just passes across the VLAN, or transits the VLAN.

[opnineopnine]

sorry but dont get the idea.

thanks. 

[Joseph W. Doherty]

Ok, a "normal" VLAN is where host devices generally reside.  I.e. traffic to those hosts starts/ends with them.  It does not carry other traffic from hosts not connected to that VLAN.

Do you understand a p2p link?  Do you understand how it carries transit traffic?  If so, a transit VLAN serves the same purpose, and like most p2p networks the transit VLAN might be configured also as a /30 or /31 network.

e.g. p2p

rtr1

int s1
 desc connects to rtr2 s1
 ip address 192.168.1.1 255.255.255.252

rtr2

int s1
 desc connects to rtr1 s1
 ip address 192.168.1.2 255.255.255.252

e.g. transit vlan

L3-1

int vlan 10
 desc connects to L3-2 vlan 10
 ip address 192.168.1.1 255.255.255.252

L3-2

int vlan 10
 desc connects to L3-1 vlan 10
 ip address 192.168.1.2 255.255.255.252