From: Thameem Maranveetil Parambath (tparamba@thecontactcentre.ae)
Date: Wed Mar 11 2009 - 04:21:57 ARST
By default cisco's STP implemenation is Per Vlan ST ... That means switch
sends BPDUs are produced seperately for each vlan.. Thats why when you
loop your interfaces which belonged to different vlans, it puts the port
in FWD state...
Try this one in MST.. map vlan 10 and 20 in instance 1, and you do this
excercise... one of the port will turn to BLK becauase here BPDUs are
created per instance...
Correct me if i am wrong..
Warm Regards,
Saketh R <saketh2083@gmail.com>
Sent by: nobody@groupstudy.com
11/03/2009 10:01 AM
Please respond to
Saketh R <saketh2083@gmail.com>
To
Cisco certification <ccielab@groupstudy.com>
cc
Subject
BPDU Exhange on Access Ports
Hi all,
I have the following topology...
I have 2 Fast Etheret ports (Fa1 and Fa2 ) which are connected (looped) .
I
have Fa1 on Vlan 10 and Fa2 on Vlan 20 . When I check the Show spanning
tree
it shows that both ports are in Fwd State . To my understanding BPDU on
access ports do not exchange Vlan information. If thats the case one of
the
port should be in Blocking state . I tried on a non cisco switch with same
scenario and I see one port is in Blocking state .
How does switch BPDU knows the ports are in different Vlans and puts in
different Vlans.
Thanks in advance!!
Saketh
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