Re: BGP Commands [7:708]
>Can anyone please explain to me what is the difference between the >command "show ip bgp" (or show ip bgp summary) and "show ip route bgp"? >I have read the BSCN book between page 348 and 352 many times, but I'm >still very confused. The book said "show ip bgp" displays BGP routing >table?? But I thought that should be "show ip route bgp". Please help. > >Regards, >Hunt Lee >IP Solution Analyst >Cable and Wireless You are dealing with two tables, at the very least. Some are conceptual or stored as part of other tables. Let me work through the flow. Incoming BGP updates, before filtering, go into the Adj-RIB-In After filtering, which is primarily on a per-peer basis, the remaining updates go into a BGP-only table called the Loc-RIB. This table contains all the BGP potential routes that passed acceptance filtering, and is router-wide. It also indicates which are the "best" BGP routes to a given destingation. "show ip bgp" displays the Loc-RIB. Next, all "best" routes from the Loc-RIB are sent to the main IP routing table, where they compete with potential routes from all other sources. "show ip route" shows the active routes to all destinations. "show ip route bgp" shows the subset of those routes that was learned from BGP. An example: BGP has two routes to 172.16.1.0/24 and to 172.16.2.0/24. It picks a best route to each. Let's say that has a next hop of 192.168.1.1 Show ip bgp would show all four, with an asterisk on the two best. The two 172.16.1.0/24 and 172.16.2.0/24 routes, with a next hop of 192.168.1.1, are sent to the main routing table installation process. Assume that the router also has a static route with administrative distance 1 to 172.16.2.0/24. That has equal specificity to the second BGP route, but the administrative distance is more preferred. When you do a "show ip route", you will see routes to both destination, but with a static source to 172.16.2.0 and a BGP source for 172.16.1.0. If you do a "show ip route bgp", you will only see the route to 172.16.1.0, because that is the only active route with a BGP source. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=711&t=708 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: BGP Commands [7:708]
Here is a little explanation. "show ip bgp" shows the bgp routing table. This may or may not be different from the IP routing table for a particular router. "show ip bgp summ" shows the EBGP & IBGP neighbor/peer relationships that a router has been able to establish. "show ip route bgp" shows all the BGP routes (both IBGP & EBGP) that have qualified to enter the IP routing table of a router. Again this may be a subset of what is being seen with the first command "show ip bgp" I have a feeling that you may still need to do a lot of reading as all this is very basic to BGP. I would also say the same thing that has been repeatedly said on this list many times that Bassam Halabi's "INTERNET ROUTING ARCHITECTURES" is one of the best books to learn about BGP. Aziz S. Islam -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Hunt Lee Sent: Sunday, April 15, 2001 9:21 AM To: [EMAIL PROTECTED] Subject: BGP Commands [7:708] Can anyone please explain to me what is the difference between the command "show ip bgp" (or show ip bgp summary) and "show ip route bgp"? I have read the BSCN book between page 348 and 352 many times, but I'm still very confused. The book said "show ip bgp" displays BGP routing table?? But I thought that should be "show ip route bgp". Please help. Regards, Hunt Lee IP Solution Analyst Cable and Wireless FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=710&t=708 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP Commands [7:708]
Here is my understanding of the difference. Hope it helps. Show ip bgp shows you the "potential routes". This is showing you the routes that are in the BGP "forwarding table". This is what BGP knows about (sometime referred to as RIB). These are the potential routes to be injected into your routing table (show ip route bgp). Your routing decision will be made from what you know in your "routing table" - the one you can view by "Show ip route bgp" command. Hope this helps (and not confuse you more). :) Raj "Hunt Lee" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Can anyone please explain to me what is the difference between the > command "show ip bgp" (or show ip bgp summary) and "show ip route bgp"? > I have read the BSCN book between page 348 and 352 many times, but I'm > still very confused. The book said "show ip bgp" displays BGP routing > table?? But I thought that should be "show ip route bgp". Please help. > > Regards, > Hunt Lee > IP Solution Analyst > Cable and Wireless > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=709&t=708 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
BGP Commands [7:708]
Can anyone please explain to me what is the difference between the command "show ip bgp" (or show ip bgp summary) and "show ip route bgp"? I have read the BSCN book between page 348 and 352 many times, but I'm still very confused. The book said "show ip bgp" displays BGP routing table?? But I thought that should be "show ip route bgp". Please help. Regards, Hunt Lee IP Solution Analyst Cable and Wireless Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=708&t=708 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
