Routing
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Routing

Route summarization for BGP

‎09-11-2018 05:29 AM

Hi Everybody,

I want ask something. I have connected to ISP, and ISP gift me IBGP Full route without default route.

my problem is my router doestn't have enough capacity for full route.

can i summary incoming route in to my router ?

for example route from 1.0.0.0 - 1.255.255.255 summarized to 1.0.0.0/8

is it possible ? or maybe any another idea ? for this case i cannot use default route to ISP router.

However, I can only configure in my router.

 

FULLROUTE.PNG

 

 

 

6 REPLIES 6
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Routing

Re: Route summarization for BGP

‎09-11-2018 07:29 AM
Hi,

You will have to ask your ISP to send you a default route instead of full table.

You can’t summarize the incoming routes (as far as I know)
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Routing

Re: Route summarization for BGP

[ Edited ]
‎09-11-2018 07:41 AM

You can try one thing and see if it works,


1. Create an import policy in which you only accept a subset of received route and install them in the routing-table.
2. Create an conditional default-route (generate route) and apply condition with the route.

i.e.

root@CE1_re# set policy-options policy-statement if-bgp term 1 from protocol bgp
[edit]
root@CE1_re# set policy-options policy-statement if-bgp term 1 then accept
[edit]
root@CE1_re# set policy-options policy-statement if-bgp term 1 then next-hop 10.1.0.1
[edit]
root@CE1_re# set policy-options policy-statement if-bgp term 2 then reject
[edit]
root@CE1_re# set routing-options generate route 0/0 policy if-bgp
[edit]

root@CE1_re# run show route 0/0
inet.0: 40 destinations, 42 routes (40 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both


0.0.0.0/0 *[Aggregate/130] 00:00:05
> to 10.1.0.1 via ge-0/0/2.0

 

If I deactivate the bgp, default route disappear.

[edit]
root@CE1_re# deactivate protocols bgp

[edit]
root@CE1_re# commit
commit complete
root@CE1_re# run show route

inet.0: 15 destinations, 15 routes (14 active, 0 holddown, 1 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.0.0/8 *[Static/5] 4d 21:20:28
> to 10.x.x.x via fxp0.0
10.1.0.0/31 *[Direct/0] 4d 20:59:30
> via ge-0/0/2.0



Activate the BGP again:

[edit]
root@CE1_re# activate protocols bgp
[edit]
root@CE1_re# commit
commit complete

[edit]
root@CE1_re# run show bgp summary
Groups: 1 Peers: 1 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0
27 25 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
10.1.0.1 100 7 2 0 0 20 25/27/27/0 0/0/0/0

[edit]
root@CE1_re# run show route

inet.0: 40 destinations, 42 routes (40 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

0.0.0.0/0 *[Aggregate/130] 00:00:25
> to 10.1.0.1 via ge-0/0/2.0
10.0.0.0/8 *[Static/5] 4d 21:21:56
> to 10.x.x.x via fxp0.0


HTH

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Routing

Re: Route summarization for BGP

‎09-11-2018 09:16 PM

Hi Bro try using aggregated routes.

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Routing

Re: Route summarization for BGP

‎09-11-2018 10:22 PM

aggregate routes have a next-hop of "reject" by default.

 

I missed the point where he mentioned that he can't use default route.

 

Aggregare route needs contributing routes. if the routes received from ISP are contiguous then again above share example can be used (same policy can be used with the aggregare routes).

 

need to accept the routes that can contribute to aggregate route 

 

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Routing

Re: Route summarization for BGP

‎10-26-2018 07:54 AM

Hello,

 

In this is use case, the unique solution is that the ISP do the summarization of routes.

In fact, the solution that have been given need the import of the routes advertised by the ISP and after that create a default route ( or you summarize the routes). Those solutions can be good for the routers in your backbone but not for the edge router ( and as I understand, the mean problem that the edge router has not enough capacity)

Iheb Boubaker
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Routing

Re: Route summarization for BGP

‎10-27-2018 07:51 AM

As an ISP connecting a customer with BGP there are typically the following options as standard across the industry.

 

Full tables (your current option)

partial tables (a subset of the internet routes closely connected to your direct ISP)

default route (this can be alone or in combination with full / partial tables)

 

Full tables would generally be used if you are multi homed and want to mix the routing tables of your multiple ISPs yourself and create your own upstream mix.  As you saw this requires a beefy router to accomadate the route table sizes today.

 

Partial tables would generally be used along with the default route if you are multihomed and you want to use the closely connected routes from both ISP and then pick one of them as the default with the other as the backup.  This is a much smaller route table and most devices can handle it.

 

Default only recieves the default route only from each ISP and you use local preference or ECMP yourself to direct the traffic.

 

From your description, all you need to do is open a change control ticket with your ISP on your BGP service and request the change from full tables to either default only.

 

Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
http://puluka.com/home
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