Hi all, Sorry, it's my ambiguous description. What I said default value is Cisco's admin distance value, eBGP is 20 and iBGP is 200. We plan to use preference to implement admin distance. Actually ,in bird, the preference of channel for BGP is BGP protocol default preference DEF_PREF_BGP ( = 100). 1) Since the configuration of preference is in channel ,if the protocol have more than one channel, does mean different channel can configure different preference in the same protocol ? 2) I also notice that " new->pref = c->preference; " in rte_update2, does mean the preference of route in route table get from preference of channel ? 3) When route selection, does mean algorithm selection compare preference of every route firstly , whether compare the preference of routes coming from same protocol ? The global best route selection algorithm is (roughly) as follows: ---> Does routes selection be processed as below sequence ? * Preferences of the routes are compared. ----> what's preference of the route, is preference in channel-config ? * Source protocol instance preferences are compared. --> what's protocol instance preference, is preference in channel-config for BGP protocol instance? * If source protocols are the same (e.g. BGP vs. BGP), the protocol's route selection algorithm is invoked. --->source protocols, iBGP and eBGP are treated as same source protocol ? * If source protocols are different (e.g. BGP vs. OSPF), result of the algorithm is undefined. The Admin distance of Cisco for eBGP and iBGP: https://supportforums.cisco.com/t5/wan-routing-and-switching/administrative-... Thanks Arvin -----Original Message----- From: Bird-users <bird-users-bounces@network.cz> On Behalf Of Robert Blayzor Sent: Tuesday, April 17, 2018 10:07 PM To: bird-users@network.cz Subject: Re: BGP route selection On 4/17/18 8:20 AM, Ondrej Zajicek wrote:
Hi
No, default value is 200 for both EBGP and IBGP. Where did you noticed 20?
20 is Cisco's default admin distance for EBGP. -- inoc.net!rblayzor XMPP: rblayzor.AT.inoc.net PGP: https://inoc.net/~rblayzor/