From: Mike Calhoon (mcalhoon27@earthlink.net)
Date: Fri Jun 25 2004 - 00:07:06 GMT-3
Hi Tom,
The DOC CD says the following:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr
_c/ipcpt3/1cfmulti.htm#1038009
<http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fip
r_c/ipcpt3/1cfmulti.htm%231038009>
"Configuring the TTL Threshold
The TTL value controls whether packets are forwarded out of an interface.
You specify the TTL value in hops. Only multicast packets with a TTL greater
than the interface TTL threshold are forwarded on the interface. The default
value is 0, which means that all multicast packets are forwarded on the
interface."
So to forward a TTL of 13 or more we need to put in "ip multicast
ttl-threshold 12"
Mike
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Tom
Rogers
Sent: Thursday, June 24, 2004 10:06 PM
To: ccielab@groupstudy.com
Subject: TTL scoping -Last time
Hi guys,
I am trying to get a handle on this TTL scoping... but some how lacking some
very fundamental. I came across this scenario, and have gone numerous times
but cannot understand it...
"Recently you have noticed suboptimal forwarding of multicast feeds
throughout your network due to problems in your unicast routing. In order to
prevent multicast feeds from looping around the network, configure R1 so
that it does not send any multicast traffic out interface E0/0 that has TTL
of less than 13"
Their answer is
int e0/0
ip multicast ttl-threhold 12
My problem is, should it it be 14. I read the Williamson Page 44 chapter 2
Multicast Basics
It says if TTL of 24 is coming into the router and it wants to go out via
int OUT, then OUT interface should have a lowere TTL than what ever is
coming in. SO it should 23 or less.
But if want Multicast not to go out then increase the TTL threshold on OUT
interface hiigher than 24
Having said... What am I thinkning wrong that answer in IE should 14 ???
Thanks
Tom
---------------------------------
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
This archive was generated by hypermail 2.1.4 : Sat Jul 03 2004 - 19:40:50 GMT-3