Thank you Priscilla for yet another awesome reply to my question. Sincerely, CN
>From: "Priscilla Oppenheimer" >Reply-To: "Priscilla Oppenheimer" >To: [EMAIL PROTECTED] >Subject: RE: ebgp-multihop default value?? [7:66157] >Date: Tue, 25 Mar 2003 21:45:20 GMT > >Cisco Nuts wrote: > > > > Hello, > > Is the ebgp-multihop default value = 255 ?? > > From all the examples that I have seen and done, it has always > > been set to a > > number ex. 2 or 200 or 255 etc. but doing an example from CCO, > > is just uses > > the cmd. # neighbor a.b.c.d ebgp-multihop - with no value and > > it works!! > > Thus, I am assuming that the ebgp-multihop default value = 255?? > > Anyone?? > > Thank you. > > Sincerely, > > CN > >Notice if you configure ebgp-multihop with no parameter, that the "show ip >bgp neighbors" output for that neighbor says: > > External BGP neighbor may be up to 255 hops away. > >If you specify a number, such as 2, you'll see: > > External BGP neighbor may be up to 2 hops away. > >Not putting a parameter on the command makes life easier, but then again, >BGP network operators don't care about easiness. :-) However, if you are >going to put a parameter, you need to know the number of hops, which can be >a little confusing because just going to a loopback on another router >instead of a directly-connected interface counts as a hop. > >I checked with a sniffer by the way. On the 3-way handshakes, the routers >use 255 for the IP TTL regardless, at least on my routers which are running >IOS 11.0. That surprised me. But after the 3-way handshake, they start >setting the TTL to 1 (if no ebgp-multihop), 255 (if ebgp-multihop is >configured with no parameter), and the correct number (if ebgp-multihop is >configured with an exact number). > >That seems like a misbehavior to me (i.e. setting the TTL to 255 for the >three-way handshake). You could establish a connection with a router even >though you couldn't do anything. You could establish so many that you could >cause a DOS. I'll have to do some more testing of this. > >Priscilla > > > > > > > > > > > > > > > > > > _________________________________________________________________ > > STOP MORE SPAM with the new MSN 8 and get 2 months FREE* > > http://join.msn.com/?page=features/junkmail _________________________________________________________________ MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. http://join.msn.com/?page=features/virus Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=66249&t=66157 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
