From: Thekkethala (thek@xxxxxxxxxxxx)
Date: Fri Nov 16 2001 - 05:47:09 GMT-3
thanks Jason for that note - to just continue this thread
If we run an IGP between the AS's - then I am wondering now ...what the use
of BGP between these AS's ?? I think its 3:40 am in the morning and my
mind's going fuzzy.
I mean in that sense, its like having an IGP setup in a way isnt it - say
like OSPF with all AS's under an area 0 type-of-thing.
To my understanding BGP really is the carrier of " WHAT routes are available
in this AS" and that info goes across the EBGP/IBGP links and ...
Inside each AS you need an IGP to ACTUALLY ROUTE around to reach those
networks inside the AS.
So now IGP's used between AS's ???
I am still stuck in a way, on the "EBGP links" between the AS's - it cant be
right to run an IGP process on an EBGP Interface ( I know yu can but in a
real world scenario it does not sound right ..or does it ??)
Dont get me wrong but I too have the same thoughts as yu and was perplexed
about BGP's role suddenly
----- Original Message -----
From: "Carnevale, Jason" <jcarnevale@gnilink.net>
To: "'Thekkethala'" <thek@mediaone.net>; "EA Louie" <elouie@yahoo.com>
Cc: "Carnevale, Jason" <jcarnevale@gnilink.net>; <ccielab@groupstudy.com>
Sent: Friday, November 16, 2001 3:04 AM
Subject: RE: A very basic question : BGP
> ok, I see what is happening. The answer to your question is no you do not
> need to add the network statement or redistribute statement at each
router.
> The problem is a return path issue. All the routers no how to reach the
> loopback because of bgp and it will make it there because everything is
> directly connected. This means the route is in the table. The problem
> is...the router in AS 1 does not know how to reach the ip address on the
> router in AS4. This is not in the table. You need to either add a loopback
> at as4 and add that to bgp, when pinging the interface on as 1 source the
> loopback on as 4 and it will work. If you want all routers to work then
you
> need to run ospf, eigrp etc.... on all the routers and put all the
> interfaces in the igp protocol and you will be set. Here is a sample
config
> for each device.
>
>
> hope this helps
>
> -Jason
>
>
> router 1:
>
> sh run
> Building configuration...
>
> Current configuration:
> !
> version 12.0
> service timestamps debug uptime
> service timestamps log uptime
> no service password-encryption
> !
> hostname r1
> !
> no logging console
> !
> ip subnet-zero
> no ip domain-lookup
> !
> !
> !
> interface Loopback0
> description SIMULATED LAN INTERFACE
> ip address 11.1.1.1 255.255.255.0
> no ip directed-broadcast
> !
> interface Ethernet0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface Serial0
> description CONNECTION TO FRAME-RELAY NETWORK
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> no ip mroute-cache
> frame-relay lmi-type ansi
> !
> interface Serial0.1 point-to-point
> description CONNECTION TO R2
> ip address 192.168.1.1 255.255.255.252
> no ip directed-broadcast
> frame-relay interface-dlci 102
> !
> interface Serial1
> no ip address
> no ip directed-broadcast
> shutdown
> !
> router ospf 110
> network 192.168.1.1 0.0.0.0 area 0
> !
> router bgp 1
> network 11.1.1.0 mask 255.255.255.0
> neighbor 192.168.1.2 remote-as 2
> neighbor 192.168.1.2 description BGP SESSION TO R2
> no auto-summary
> !
> ip classless
> !
> !
> !
> line con 0
> exec-timeout 0 0
> transport input none
> escape-character 3
> line aux 0
> line vty 0 4
> login
> !
> end
>
> r1#term len 0
> r1#sh ip ro
> Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
> E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
> i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate
> default
> U - per-user static route, o - ODR
> T - traffic engineered route
>
> Gateway of last resort is not set
>
> 11.0.0.0/24 is subnetted, 1 subnets
> C 11.1.1.0 is directly connected, Loopback0
> 192.168.1.0/30 is subnetted, 3 subnets
> O 192.168.1.8 [110/192] via 192.168.1.2, 00:00:57, Serial0.1
> C 192.168.1.0 is directly connected, Serial0.1
> O 192.168.1.4 [110/128] via 192.168.1.2, 00:00:57, Serial0.1
> r1#sh ip bgp
> BGP table version is 2, local router ID is 192.168.1.1
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> *> 11.1.1.0/24 0.0.0.0 0 32768 i
> r1#
>
> router 2
>
> sh run
> Building configuration...
>
> Current configuration:
> !
> version 12.0
> service timestamps debug uptime
> service timestamps log uptime
> no service password-encryption
> !
> hostname R2
> !
> logging buffered 10000 debugging
> no logging console
> !
> ip subnet-zero
> no ip domain-lookup
> !
> !
> !
> interface Serial0
> description CONNECTION TO FRAME-RELAY NETWORK
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> no ip mroute-cache
> no fair-queue
> frame-relay lmi-type ansi
> !
> interface Serial0.1 point-to-point
> description CONNECTION TO R1
> ip address 192.168.1.2 255.255.255.252
> no ip directed-broadcast
> frame-relay interface-dlci 201
> !
> interface Serial0.2 point-to-point
> description CONNECTION TO R3
> ip address 192.168.1.5 255.255.255.252
> no ip directed-broadcast
> frame-relay interface-dlci 203
> !
> interface Serial1
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface TokenRing0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> router ospf 110
> network 192.168.1.2 0.0.0.0 area 0
> network 192.168.1.5 0.0.0.0 area 0
> !
> router bgp 2
> neighbor 192.168.1.1 remote-as 1
> neighbor 192.168.1.1 description BGP SESSION TO R1
> neighbor 192.168.1.6 remote-as 3
> neighbor 192.168.1.6 description BGP SESSION TO R3
> !
> ip classless
> !
> !
> !
> line con 0
> exec-timeout 0 0
> transport input none
> line aux 0
> line vty 0 4
> !
> end
>
> R2# sh ip ro
> Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
> E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
> i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate
> default
> U - per-user static route, o - ODR
> T - traffic engineered route
>
> Gateway of last resort is not set
>
> 11.0.0.0/24 is subnetted, 1 subnets
> B 11.1.1.0 [20/0] via 192.168.1.1, 00:08:50
> 192.168.1.0/30 is subnetted, 3 subnets
> O 192.168.1.8 [110/128] via 192.168.1.6, 00:01:30, Serial0.2
> C 192.168.1.0 is directly connected, Serial0.1
> C 192.168.1.4 is directly connected, Serial0.2
> R2#sh ip bgp
> BGP table version is 2, local router ID is 192.168.1.5
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> *> 11.1.1.0/24 192.168.1.1 0 0 1 i
> R2#
>
>
> router 3
>
> sh run
> Building configuration...
>
> Current configuration:
> !
> version 12.0
> service timestamps debug uptime
> service timestamps log uptime
> no service password-encryption
> !
> hostname R3
> !
> logging buffered 10000 debugging
> no logging console
> !
> ip subnet-zero
> no ip domain-lookup
> !
> !
> !
> interface Ethernet0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface Serial0
> description CONNECTION TO FRAME-RELAY NETWORK
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> no ip mroute-cache
> no fair-queue
> frame-relay lmi-type ansi
> !
> interface Serial0.1 point-to-point
> description CONNECTION TO R2
> ip address 192.168.1.6 255.255.255.252
> no ip directed-broadcast
> frame-relay interface-dlci 302
> !
> interface Serial0.2 point-to-point
> description CONNECTION TO R4
> ip address 192.168.1.9 255.255.255.252
> no ip directed-broadcast
> frame-relay interface-dlci 304
> !
> interface Serial1
> no ip address
> no ip directed-broadcast
> shutdown
> !
> router ospf 110
> network 192.168.1.6 0.0.0.0 area 0
> network 192.168.1.9 0.0.0.0 area 0
> !
> router bgp 3
> neighbor 192.168.1.5 remote-as 2
> neighbor 192.168.1.5 description BGP SESSION TO R2
> neighbor 192.168.1.10 remote-as 4
> neighbor 192.168.1.10 description BGP SESSION TO R4
> !
> ip classless
> !
> !
> !
> line con 0
> exec-timeout 0 0
> transport input none
> line aux 0
> line vty 0 4
> !
> end
>
> R3# sh ip ro
> Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
> E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
> i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate
> default
> U - per-user static route, o - ODR
> T - traffic engineered route
>
> Gateway of last resort is not set
>
> 11.0.0.0/24 is subnetted, 1 subnets
> B 11.1.1.0 [20/0] via 192.168.1.5, 00:09:36
> 192.168.1.0/30 is subnetted, 3 subnets
> C 192.168.1.8 is directly connected, Serial0.2
> O 192.168.1.0 [110/128] via 192.168.1.5, 00:02:23, Serial0.1
> C 192.168.1.4 is directly connected, Serial0.1
> R3#sh ip bgp
> BGP table version is 3, local router ID is 192.168.1.9
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> *> 11.1.1.0/24 192.168.1.5 0 2 1 i
> R3#
>
> router 4
>
> sh run
> Building configuration...
>
> Current configuration:
> !
> version 12.0
> service timestamps debug uptime
> service timestamps log uptime
> no service password-encryption
> !
> hostname R4
> !
> logging buffered 10000 debugging
> no logging console
> !
> ip subnet-zero
> no ip domain-lookup
> isdn switch-type basic-5ess
> !
> !
> !
> interface Serial0
> description CONNECTION TO FRAME-RELAY NETWORK
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> ip ospf network point-to-multipoint
> no ip mroute-cache
> no fair-queue
> frame-relay lmi-type ansi
> !
> interface Serial0.1 point-to-point
> description CONNECTION TO R3
> ip address 192.168.1.10 255.255.255.252
> no ip directed-broadcast
> frame-relay interface-dlci 403
> !
> interface Serial1
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface TokenRing0
> description CONNECTION TO R6 TO0
> no ip address
> no ip directed-broadcast
> ip ospf authentication-key cisco
> ip ospf cost 1
> ip ospf priority 100
> shutdown
> ring-speed 16
> !
> interface BRI0
> no ip address
> no ip directed-broadcast
> shutdown
> isdn switch-type basic-5ess
> !
> router ospf 110
> network 192.168.1.10 0.0.0.0 area 0
> !
> router bgp 4
> neighbor 192.168.1.9 remote-as 3
> neighbor 192.168.1.9 description BGP SESSION TO R3
> !
> ip classless
> !
> !
> !
> line con 0
> exec-timeout 0 0
> transport input none
> escape-character 3
> line aux 0
> line vty 0 4
> login
> !
> end
>
> R4# sh ip ro
> Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
> E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
> i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate
> default
> U - per-user static route, o - ODR
> T - traffic engineered route
>
> Gateway of last resort is not set
>
> 11.0.0.0/24 is subnetted, 1 subnets
> B 11.1.1.0 [20/0] via 192.168.1.9, 00:10:01
> 192.168.1.0/30 is subnetted, 3 subnets
> C 192.168.1.8 is directly connected, Serial0.1
> O 192.168.1.0 [110/192] via 192.168.1.9, 00:02:41, Serial0.1
> O 192.168.1.4 [110/128] via 192.168.1.9, 00:02:41, Serial0.1
> R4#sh ip bgp
> BGP table version is 2, local router ID is 192.168.1.10
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> *> 11.1.1.0/24 192.168.1.9 0 3 2 1 i
> R4#ping 11.1.1.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 11.1.1.1, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 172/172/176 ms
> R4#
>
> frame-switch
>
> term len 0
> FRAME-SW#sh run
> Building configuration...
>
> Current configuration:
> !
> version 12.0
> service timestamps debug uptime
> service timestamps log uptime
> no service password-encryption
> !
> hostname FRAME-SW
> !
> logging buffered 10000 debugging
> no logging console
> !
> ip subnet-zero
> no ip domain-lookup
> frame-relay switching
> !
> !
> !
> !
> !
> interface Ethernet0/0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface Serial1/0
> no ip address
> no ip directed-broadcast
> no ip mroute-cache
> shutdown
> no fair-queue
> !
> interface Serial1/1
> description CONNECTION TO R1 S0
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> clockrate 64000
> frame-relay lmi-type ansi
> frame-relay intf-type dce
> frame-relay route 102 interface Serial1/2 201
> !
> interface Serial1/2
> description CONNECTION TO R2 S0
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> clockrate 64000
> frame-relay lmi-type ansi
> frame-relay intf-type dce
> frame-relay route 201 interface Serial1/1 102
> frame-relay route 203 interface Serial1/3 302
> !
> interface Serial1/3
> description CONNECTION TO R3 S0
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> clockrate 64000
> frame-relay lmi-type ansi
> frame-relay intf-type dce
> frame-relay route 302 interface Serial1/2 203
> frame-relay route 304 interface Serial1/4 403
> !
> interface Serial1/4
> description CONNECTION TO R4 S0
> no ip address
> no ip directed-broadcast
> encapsulation frame-relay IETF
> clockrate 64000
> frame-relay lmi-type ansi
> frame-relay intf-type dce
> frame-relay route 403 interface Serial1/3 304
> !
> interface Serial1/5
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface Serial1/6
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface Serial1/7
> no ip address
> no ip directed-broadcast
> shutdown
> !
> ip classless
> !
> !
> line con 0
> exec-timeout 0 0
> transport input none
> line aux 0
> line vty 0 4
> !
> end
>
> FRAME-SW#
>
> -----Original Message-----
> From: Thekkethala [mailto:thek@mediaone.net]
> Sent: Friday, November 16, 2001 2:39 AM
> To: EA Louie
> Cc: jcarnevale@gnilink.net; ccielab@groupstudy.com
> Subject: Re: A very basic question : BGP
>
>
> apologise for not being clear ....
>
> The query really is : Do I need to redistribute by directly connected
(Ebgp)
> links that are setup between AS's,into bgp at each of the routers in the
> example ?
>
> I just found out that when i did a redistribute connected (under bgp) on
all
> of the routers - the ping goes through from AS4 to the loopback address on
> AS1 ?? My BGP table grew too as a result of all the entries ...
>
> Therefore : sounds like EBGP links need to be explicitly brought into the
> "bgp table" across all routers for an end to end IP connectivity to happen
> (network/redistribute connected...)
>
> sounds a bit off .... or i am missing something elementary !!!
>
> ----- Original Message -----
> From: "EA Louie" <elouie@yahoo.com>
> To: "Thekkethala" <thek@mediaone.net>; <ccielab@groupstudy.com>
> Sent: Friday, November 16, 2001 2:18 AM
> Subject: Re: A very basic question : BGP
>
>
> > Try doing a traceroute to see where your ping is failing. Post those
> > results. Also, try your ping/traceroute from AS1 to AS4 and post those
> > results.
> >
> > -e-
> >
> > ----- Original Message -----
> > From: "Thekkethala" <thek@mediaone.net>
> > To: <ccielab@groupstudy.com>
> > Sent: Thursday, November 15, 2001 10:49 PM
> > Subject: A very basic question : BGP
> >
> >
> > > Just a sudden 'shake-up' in my fundamentals all of a sudden
> > >
> > > Here is the clarification. (EBGP links - do they need to be leaked
???)
> > >
> > > 1. You have multiple AS's and have EBGP running between them all.
> > >
> > > as1 ------->as2----->as3------->as4 (a single router in each AS for
> > example)
> > >
> > > lets say yu configure a loopback address in as1 and leak it into bgp
> via
> > a
> > > network statement in as1.
> > >
> > > Now, keeping the config (basic) as is, yu sit on the router on as4 and
> try
> > a
> > > ping back to as1 to this interface. It does no go thru. However all
the
> > BGP
> > > tables enroute indicate this entry and since they are directly
> connected
> > ebgp
> > > setups, the next hop are there in the ip routing table as well
(directly
> > > connected).I then did a redistribute-connected under the bgp process
on
> > ALL
> > > the routers and tried again - no luck in reaching the loopback address
> in
> > as1
> > > FROM as4 - however from as2 no problems / as3 and as4 no go at all !!
> > >
> > > My Question>
> > > 1. The eBGP links between routers :
> > >
> > > Do we ALWAYS need to consciously redistribute them in BGP setup
> > > (using either the redistribute-connected or network statement along
with
> a
> > no
> > > auto-summary) to enable a ping / traceroute etc .. for ip basically
> > > ...........
> > >
> > > I am sorry if this sounds really elementary ... but am quite puzzled -
> > what if
> > > I have a setup involving 50/60 ebgp session (in theory I mean)
....!!!!!
This archive was generated by hypermail 2.1.4 : Fri Jun 21 2002 - 06:45:16 GMT-3