VLAN trunking question

Discussion in 'Cisco' started by professorguy, Sep 15, 2006.

  1. professorguy

    professorguy

    Joined:
    Sep 15, 2006
    Messages:
    39
    I have theoretical question for some switch jockey out there:

    My network consists of two clients (A & B) on a Layer-3 switch (S1) which is trunked to another L3 switch (S2) which has a client (C). Simple:

    (A)--(B)-----(S1)=======(S2)------(C)

    All three clients are on the same VLAN (VLAN 10) and also on the same subnet (192.168.10.x / 24).

    My question: If (A) talks to (B) is switch (S1) smart enough to know that it doesn't have to forward the traffic on the trunk? Everything I read says if C is on VLAN 10 then (S2) WILL get traffic. But if the switch is really a L3 switch (it can tell e.g. port 4 gets 192.168.10.222), can't it also realize that if port 4 is 192.168.10.222, then .222 cannot be off (S2) and so shouldn't be sent over the trunk?

    The L3 switches in question happen to be Cisco 3750's.

    I know that subnetting (C) out and putting it on a different VLAN will deal with the replication over the trunk, but I'm trying to troubleshoot an existing setup.

    Thanks in advance for any light that can be shed here.

    ><professorguy
     
    professorguy, Sep 15, 2006
    #1
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. DaZZa
    Replies:
    0
    Views:
    652
    DaZZa
    Feb 16, 2004
  2. Bill F

    pix vlan trunking

    Bill F, May 3, 2004, in forum: Cisco
    Replies:
    4
    Views:
    4,174
    Walter Roberson
    May 4, 2004
  3. BG
    Replies:
    4
    Views:
    12,453
  4. Michael Letchworth

    Trunking VLAN to non cisco switch?

    Michael Letchworth, Dec 9, 2004, in forum: Cisco
    Replies:
    3
    Views:
    1,571
  5. tjiang@computeredservices.com

    setup VLAN trunking between 2924 switch and 2611 router

    tjiang@computeredservices.com, Dec 30, 2004, in forum: Cisco
    Replies:
    5
    Views:
    9,576
    Walter Roberson
    Jan 2, 2005
Loading...

Share This Page