did a lab to find the truth
R4#show ip bgp 1.1.1.0
BGP routing table entry for 1.1.1.0/24, version 4
Paths: (2 available, best #2, table Default-IP-Routing-Table)
Advertised to update-groups:
1
12
10.0.0.1 from 20.0.0.3 (20.0.0.3)
--------------------------IBGP Neighbor----------------
Origin IGP, metric 0, localpref 100, valid,* internal*
12
20.0.0.2 from 20.0.0.2 (20.0.0.2)
-------------------------EBGP Neighobr------------
Origin IGP, localpref 100, valid, *external, best*
now bumping up the AD for external routes
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
B * 1.1.1.0 [220/0] via 20.0.0.2,* 00:00:08
20.0.0.0/24 is subnetted, 1 subnets
C 20.0.0.0 is directly connected, Ethernet0/1
10.0.0.0/24 is subnetted, 1 subnets
S 10.0.0.0 [1/0] via 20.0.0.3
still the next hop is egp neighbor ...hence AD is not used by BGP
for selecting best path ...
*thanks you guys !!*
On Sat, Nov 30, 2013 at 6:47 PM, Samir Idris <[email protected]> wrote:
> Imran,
>
> AD is not one of the attribute in BGP's path selection algorithm. EBGP
> route will always be preferred over IBGP route provided all the prior path
> selection attributed are equal.
>
> Go through the link below:
>
>
> http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml
>
> I hope this clarifies.
>
> Regards,
> Samir Idris.
>
> Sent from my iPhone
>
> > On 30 Nov 2013, at 8:27 pm, Imran Ali <[email protected]> wrote:
> >
> > Hi Narendra ,
> >
> > you are correct , AD is generally thought to be used as a tie
> > breaker with different protocols... but not always ,
> >
> > AD can be used to decide routes of same protocol !!
> >
> > changing AD of ebgp to 201 forces ibgp routes...to get into the routing
> > table.....
> >
> >
> > On Sat, Nov 30, 2013 at 12:25 PM, Narendra Naukwal
> > <[email protected]>wrote:
> >
> >> Hi Taqdir,
> >>
> >> It can be used when BGP as a protocol is competing with a different
> >> protocol for exact same Prefix/prefix-length.
> >>
> >>
> >> Thanks,
> >> Narendra Naukwal
> >>
> >>
> >>
> >>
> >> On Saturday, 30 November 2013 12:42 PM, Marko Milivojevic <
> >> [email protected]> wrote:
> >>
> >> Taqdir,
> >>
> >> AD will not impact bestpath selection process, but will impact
> selection of
> >> the best route between different routing sources.
> >>
> >> What you might want to look at is the bestpath selection process and
> >> manipulate one of the appropriate BGP attributes to prefer internal over
> >> external route:
> >>
> >>
> >>
> http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml
> >>
> >> --
> >> Marko Milivojevic - CCIE #18427 (SP R&S)
> >> Senior CCIE Instructor / Managing Partner - IPexpert
> >> :: Free Video Training: http://youtube.com/IPexpertInc
> >> :: Social: http://twitter.com/@icemarkom | http://fb.me/ccie18427
> >> :: IPexpert: http://www.ipexpert.com/Communities | +1-810-326-1444
> >>
> >>
> >>
> >> On Fri, Nov 29, 2013 at 10:49 PM, Taqdir Singh <[email protected]
> >>> wrote:
> >>
> >>> Hi Team,
> >>>
> >>>
> >>> Changing AD of eBGP to 201 doesnt install iBGP route..
> >>>
> >>> if changing AD of BGP doest effect path selection then for what purpose
> >>> distance command is there in router bgp ?
> >>>
> >>> --
> >>>
> >>>
> >>> Thanks & regards,
> >>>
> >>> Taqdir Singh
> >>> Ph: (+91) 8826009496
> >>> _______________________________________________
> >>> Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos
> ::
> >>>
> >>> iPexpert on YouTube: www.youtube.com/ipexpertinc
> >>
> >> _______________________________________________
> >> Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos ::
> >>
> >> iPexpert on YouTube: www.youtube.com/ipexpertinc
> >> _______________________________________________
> >> Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos ::
> >>
> >> iPexpert on YouTube: www.youtube.com/ipexpertinc
> > _______________________________________________
> > Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos ::
> >
> > iPexpert on YouTube: www.youtube.com/ipexpertinc
>
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