Re: BGP, TCP server-client

Muhammad,

Ok. Now I am in front of few routers, here we have 2 routers R5 and R6. I
knew we had to mess with the IP but this is one solution that you can add to
the list.

*On R6*

interface Loopback0

 ip address 6.6.6.6 255.0.0.0

!

interface FastEthernet0/0

 ip address 10.1.12.6 255.255.255.0

*R6#sh run | s router*

router bgp 600

 neighbor 5.5.5.5 remote-as 500

 neighbor 5.5.5.5 ebgp-multihop 255

 neighbor 5.5.5.5 update-source Loopback0

 no auto-summary

*ip route 0.0.0.0 0.0.0.0 10.1.12.6*

*On R6*

* *

interface Loopback0

 ip address 6.6.6.6 255.0.0.0

!

interface FastEthernet0/0

 ip address 10.1.12.6 255.255.255.0

*R6#sh run | S router*

router bgp 600

 no synchronization

 bgp log-neighbor-changes

 neighbor 5.5.5.5 remote-as 500

 neighbor 5.5.5.5 ebgp-multihop 255

 neighbor 5.5.5.5 update-source Loopback0

 no auto-summary

* *

*ip route 5.5.5.5 255.255.255.255 10.1.12.5*

*Now to test:*

* *

*On R5*

*R5#Show ip bgp nei | Inc port*

Local host: 5.5.5.5, *Local port: 179*

Foreign host: 6.6.6.6, Foreign port: 14288

*R5#cle ip bgp **

*R5#Show ip bgp nei | Inc port*

Local host: 5.5.5.5, *Local port: 179*

Foreign host: 6.6.6.6, Foreign port: 27541

*R5#cle ip bgp **

*R5#Show ip bgp nei | Inc port*

Local host: 5.5.5.5, *Local port: 179*

Foreign host: 6.6.6.6, Foreign port: 24861

*R5#cle ip bgp **

*R5#Show ip bgp nei | Inc port*

Local host: 5.5.5.5, *Local port: 179*

Foreign host: 6.6.6.6, Foreign port: 28284

*On R6*

*R6#Show ip bgp nei | Inc port*

Local host: 6.6.6.6, Local port: 28284

Foreign host: 5.5.5.5, *Foreign port: 179*

* *

*R6#cle ip bgp **

*R6#Show ip bgp nei | Inc port*

Local host: 6.6.6.6, Local port: 50490

Foreign host: 5.5.5.5, *Foreign port: 179*

* *

*R6#cle ip bgp **

*R6#Show ip bgp nei | Inc port*

Local host: 6.6.6.6, Local port: 17509

Foreign host: 5.5.5.5, *Foreign port: 179*

*R6#cle ip bgp **

*R6#Show ip bgp nei | Inc port*

Local host: 6.6.6.6, Local port: 50009

Foreign host: 5.5.5.5, *Foreign port: 179*

Thanks
On Fri, Oct 16, 2009 at 3:41 AM, Muhammad Anser Khan
<manserkhan_at_gmail.com>wrote:

> Here is the configuration with the output:
>
> Router R1
>
> interface Loopback0
> ip address 1.1.1.1 255.0.0.0
> !
> interface FastEthernet0/0
> ip address 10.1.1.1 255.255.255.0
> duplex auto
> speed auto
> !
> interface FastEthernet0/1
> no ip address
> shutdown
> duplex auto
> speed auto
> !
> router bgp 100
> no synchronization
> bgp log-neighbor-changes
> neighbor 10.1.1.2 remote-as 200
> neighbor 10.1.1.2 ebgp-multihop 255
> neighbor 10.1.1.2 update-source Loopback0
> no auto-summary
>
> Router R2:
> !
> interface FastEthernet0/0
> ip address 10.1.1.2 255.255.255.0
> duplex auto
> speed auto
> !
> interface FastEthernet0/1
> no ip address
> shutdown
> duplex auto
> speed auto
> !
> router bgp 200
> no synchronization
> bgp log-neighbor-changes
> neighbor 1.1.1.1 remote-as 100
> neighbor 1.1.1.1 ebgp-multihop 255
> no auto-summary
> !
> ip http server
> no ip http secure-server
> ip route 1.1.1.1 255.255.255.255 10.1.1.1
>
> OUTPUT R1:
>
> R1#show ip bgp neighbors | inc port
> Local host: 1.1.1.1, Local port: 179
> Foreign host: 10.1.1.2, Foreign port: 45023
> (Server)
>
> R1#clear ip bgp *
>
> R1#show ip bgp neighbors | inc port
> Local host: 1.1.1.1, Local port: 24572
> Foreign host: 10.1.1.2, Foreign port: 179
> (Client)
> R2#sh ip bgp nei | inc port
> Local host: 10.1.1.2, Local port: 179
> Foreign host: 1.1.1.1, Foreign port: 25330
> (Server)
> Initial OUTPUT R2:
>
> R2#sh ip bgp nei | inc port
> Local host: 10.1.1.2, Local port: 45023
> Foreign host: 1.1.1.1, Foreign port: 179
> (Client)
>
> It changes their relationship simultaneously
>
> Regards,
> Anser
>
> On Fri, Oct 16, 2009 at 3:38 AM, Narbik Kocharians <narbikk_at_gmail.com>
> wrote:
> > I was referring to setting up client and server ONLY. Update-source does
> NOT
> > change the BGP-ID, it changes the source ip address, therefore, if you
> have
> > two routers let's say R1 and R2, and R1 is configured to establish the
> BGP
> > session using the IP address of R2's link and R2 establishes the BGP
> session
> > with the loopback Ip address of R1. You would need update-source lo0 on
> R1
> > and that will make R1 the client and R2 the server.
> >
> > Once again i am NOT infront of a rack but this would be the config:
> >
> > On R1
> > int lo0
> > ip addr 1.1.1.1 255.0.0.0
> > int f0/0
> > ip addr 10.1.1.1 255.255.255.0
> >
> > router bgp 100
> > neighbor 10.1.1.2 remot 200
> > neighbor 10.1.1.2 update-source lo0
> > neighbor 10.1.1.2 ebgp-multi
> >
> > On R2
> >
> > ip route 1.1.1.1 255.255.255.255 10.1.1.1
> >
> > int f0/0
> > ip addr 10.1.1.2 255.255.255.0
> >
> > router bgp 200
> > neighbor 1.1.1.1 remot 100
> > neighbor 1.1.1.1 ebgp-multi
> >
> > This should make R1 the client and R2 the server, if you lab it up it
> should
> > work. If i was infront of a rack i would have sent you the actual config.
> >
> > On Thu, Oct 15, 2009 at 3:32 PM, Muhammad Anser Khan <
> manserkhan_at_gmail.com>
> > wrote:
> >>
> >> I dont think so, update-source just change your BGP ID and This will
> >> help you when collision occurs only(higher ID will be the winner). You
> >> can check it by clear ip bgp * on both the routers one by one after
> >> applying this command.It will change the server and client
> >> simultaneously.
> >>
> >> Otherwise any one can be server/client by default.
> >>
> >> Regards,
> >> Anser
> >>
> >> On Thu, Oct 15, 2009 at 10:45 PM, Narbik Kocharians <narbikk_at_gmail.com>
> >> wrote:
> >> > Have you tried the update-source? that is another way to control the
> >> > client/server role. I am not infront of a rack, but when you think
> about
> >> > it
> >> > you should be able to manipulate that on one end to do this.
> >> >
> >> > On Wed, Oct 14, 2009 at 10:33 AM, Muhammad Anser Khan
> >> > <manserkhan_at_gmail.com>
> >> > wrote:
> >> >>
> >> >> My conclusion is here after applying all the scenarios on the
> dynamics
> >> >> :)
> >> >>
> >> >> R1#sh ip bgp neighbors | inc port
> >> >> Local host: 192.168.1.2, Local port: 179
> >> >> Foreign host: 192.168.1.1, Foreign port: 30434
> >> >>
> >> >> Above output means R1 is the 'Server'. R0 (192.168.1.1) initiates the
> >> >> connection (which is client)
> >> >>
> >> >> There are two ways I found to restrict the Server/Client.
> >> >>
> >> >> 1- By using ACL on the interface:
> >> >> You can restrict who will be the server and the client.
> >> >> (Active/passive)
> >> >>
> >> >> 2 - By giving this command on the R1:
> >> >> neighbor 192.168.1.1 transport connection-mode passive
> >> >>
> >> >> R1 always be the server now means never initiate the TCP
> >> >> connection(Only receive the connection from R0)
> >> >>
> >> >> Another point as mentioned in the RFC that higher BGP ID will be
> match
> >> >> when collision occurs only otherwise any one can be the server/client
> >> >> by default.
> >> >>
> >> >> Regards,
> >> >> Anser
> >> >>
> >> >> On Wed, Oct 14, 2009 at 10:11 AM, Marcel Lammerse <
> m.lammerse_at_mac.com>
> >> >> wrote:
> >> >> > Hey Marco,
> >> >> >
> >> >> > you're spot on. Thanks for clarifying that, I learnt another thing
> >> >> > about
> >> >> > BGP
> >> >> > today :) The only way to set the client and server is through
> either
> >> >> > the
> >> >> > neighbor transport command, or an inbound acl, as you already
> pointed
> >> >> > out.
> >> >> >
> >> >> > Cheers,
> >> >> > Marcel
> >> >> >
> >> >> >
> >> >> >
> >> >> > On 14/10/2009, at 01:39 , Marko Milivojevic wrote:
> >> >> >
> >> >> >> I think you are misunderstanding something from that RFC. It is
> very
> >> >> >> clear in section 8.2.x.y that every peer is both active and
> passive,
> >> >> >> unless otherwise configured. It also explicitly states that peer
> >> >> >> configured as active, can become either active or passive. Here is
> >> >> >> the
> >> >> >> exact quote:
> >> >> >>
> >> >> >> 8.2.1.1. Terms "active" and "passive"
> >> >> >>
> >> >> >> The terms active and passive have been in the Internet operator's
> >> >> >> vocabulary for almost a decade and have proven useful. The words
> >> >> >> active and passive have slightly different meanings when applied
> to
> >> >> >> a
> >> >> >> TCP connection or a peer. There is only one active side and one
> >> >> >> passive side to any one TCP connection, per the definition above
> >> >> >> and
> >> >> >> the state machine below. When a BGP speaker is configured as
> >> >> >> active,
> >> >> >> it may end up on either the active or passive side of the
> >> >> >> connection
> >> >> >> that eventually gets established. Once the TCP connection is
> >> >> >> completed, it doesn't matter which end was active and which was
> >> >> >> passive. The only difference is in which side of the TCP
> >> >> >> connection
> >> >> >> has port number 179.
> >> >> >>
> >> >> >> It takes some experience and practice to actually understand this,
> >> >> >> but
> >> >> >> let me try in a brief message.
> >> >> >>
> >> >> >> As you all have correctly observed, operation when both peers are
> >> >> >> active is pretty random. It's hard to determine which peer will be
> >> >> >> passive which will be active - and that's perfectly fine. Rare are
> >> >> >> occasions in which this even remotely matters. In fact, this helps
> >> >> >> speed things up somewhat. Given that routers will not be trying at
> >> >> >> the
> >> >> >> same time to establish connection (be active) and they both
> listen,
> >> >> >> as
> >> >> >> soon as one opens connection, the other will stop trying to be
> >> >> >> active
> >> >> >> and session is established. THERE IS NO COLLISION!
> >> >> >>
> >> >> >> In those rare cases when both try at the same time, connection
> >> >> >> collision occurs and section 6.8 of the RFC applies, as it was
> >> >> >> clearly
> >> >> >> written in the first paragraph of it.
> >> >> >>
> >> >> >> Kind regards,
> >> >> >> Marko.
> >> >> >>
> >> >> >> --
> >> >> >> Marko
> >> >> >> CCIE #18427 (SP)
> >> >> >> My network blog: http://cisco.markom.info/
> >> >> >>
> >> >> >> On Tue, Oct 13, 2009 at 09:17, Marcel Lammerse <
> m.lammerse_at_mac.com>
> >> >> >> wrote:
> >> >> >>>
> >> >> >>> I just labbed this up and, to my surprise, I got the same
> results.
> >> >> >>> According
> >> >> >>> to rfc 4271, the bgp router-id should determine which side
> becomes
> >> >> >>> the
> >> >> >>> server and which becomes the client during a connection
> collision.
> >> >> >>> This
> >> >> >>> should be a deterministic process. But in my lab it made no
> >> >> >>> difference
> >> >> >>> and I
> >> >> >>> got random results. Why?
> >> >> >>>
> >> >> >>> The neighbor transport command seems to lock the client/server
> role
> >> >> >>> down.
> >> >> >>> The passive side is the server, the active side is the client.
> >> >> >>>
> >> >> >>> On 13/10/2009, at 15:57 , Marko Milivojevic wrote:
> >> >> >>>
> >> >> >>>> Have you tried:
> >> >> >>>>
> >> >> >>>> neighbor X.X.X.X transport connection-mode active
> >> >> >>>>
> >> >> >>>> Out of curiosity - is this a lab requirement, or are you trying
> to
> >> >> >>>> do
> >> >> >>>> something weird in real life? :-)
> >> >> >>>>
> >> >> >>>> --
> >> >> >>>> Marko
> >> >> >>>> CCIE #18427 (SP)
> >> >> >>>> My network blog: http://cisco.markom.info/
> >> >> >>>>
> >> >> >>>> On Tue, Oct 13, 2009 at 03:49, ospfv2 <ospfv2_at_gmail.com> wrote:
> >> >> >>>>>
> >> >> >>>>> Hi Experts
> >> >> >>>>>
> >> >> >>>>> afaik to make bgp router as tcp client, we can set the
> router-id
> >> >> >>>>> higher or put update-source command. is that correct ?
> >> >> >>>>>
> >> >> >>>>> but i found out if we reload each of the router,sometime the
> >> >> >>>>> client
> >> >> >>>>> become the server.
> >> >> >>>>> how to make the assigment permanent ?
> >> >> >>>>>
> >> >> >>>>> any comments ?
> >> >> >>>>>
> >> >> >>>>> thx
> >> >> >>>>>
> >> >> >>>>>
> >> >> >>>>>
> >> >> >>>>> R1# sh run
> >> >> >>>>> interface FastEthernet0/0
> >> >> >>>>> B ip address 192.168.1.1 255.255.255.0
> >> >> >>>>>
> >> >> >>>>> router bgp 100
> >> >> >>>>> B no synchronization
> >> >> >>>>> B neighbor 192.168.1.2 remote-as 200
> >> >> >>>>> B no auto-summary
> >> >> >>>>>
> >> >> >>>>> R1#sh ip bgp nei | in port
> >> >> >>>>> Local host: 192.168.1.1, Local port: 179
> >> >> >>>>> Foreign host: 192.168.1.2, Foreign port: 11001
> >> >> >>>>>
> >> >> >>>>>
> >> >> >>>>>
> >> >> >>>>>
> >> >> >>>>> R2#sh run
> >> >> >>>>> interface FastEthernet0/0
> >> >> >>>>> B ip address 192.168.1.2 255.255.255.0
> >> >> >>>>>
> >> >> >>>>> router bgp 200
> >> >> >>>>> B no synchronization
> >> >> >>>>> B neighbor 192.168.1.1 remote-as 100
> >> >> >>>>> B neighbor 192.168.1.1 update-source FastEthernet0/0
> >> >> >>>>> B no auto-summary
> >> >> >>>>>
> >> >> >>>>>
> >> >> >>>>> R2# sh ip bgp nei | in port
> >> >> >>>>> Local host: 192.168.1.2, Local port: 11001
> >> >> >>>>> Foreign host: 192.168.1.1, Foreign port: 179
> >> >> >>>>
> >> >> >>>>
> >> >> >>>> Blogs and organic groups at http://www.ccie.net
> >> >> >>>>
> >> >> >>>>
> >> >> >>>>
> >> >> >>>>
> _______________________________________________________________________
> >> >> >>>> Subscription information may be found at:
> >> >> >>>> http://www.groupstudy.com/list/CCIELab.html
> >> >> >>
> >> >> >>
> >> >> >> Blogs and organic groups at http://www.ccie.net
> >> >> >>
> >> >> >>
> >> >> >>
> _______________________________________________________________________
> >> >> >> Subscription information may be found at:
> >> >> >> http://www.groupstudy.com/list/CCIELab.html
> >> >> >
> >> >> >
> >> >> > Blogs and organic groups at http://www.ccie.net
> >> >> >
> >> >> >
> >> >> >
> _______________________________________________________________________
> >> >> > Subscription information may be found
> >> >> > at:http://www.groupstudy.com/list/CCIELab.html
> >> >>
> >> >>
> >> >> Blogs and organic groups at http://www.ccie.net
> >> >>
> >> >>
> _______________________________________________________________________
> >> >> Subscription information may be found at:
> >> >> http://www.groupstudy.com/list/CCIELab.html
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >> >
> >> > --
> >> > Narbik Kocharians
> >> > CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> >> > www.MicronicsTraining.com <http://www.micronicstraining.com/>
> >> > Sr. Technical Instructor
> >> > YES! We take Cisco Learning Credits!
> >> > Training And Remote Racks available
> >> >
> >
> >
> >
> > --
> > Narbik Kocharians
> > CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> > www.MicronicsTraining.com <http://www.micronicstraining.com/>
> > Sr. Technical Instructor
> > YES! We take Cisco Learning Credits!
> > Training And Remote Racks available
> >
>

--
Narbik Kocharians
CCSI#30832, CCIE# 12410 (R&S, SP, Security)
www.MicronicsTraining.com
Sr. Technical Instructor
YES! We take Cisco Learning Credits!
Training And Remote Racks available
Blogs and organic groups at http://www.ccie.net