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manzur
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CCR1072 with 2 Provders BGP Full Tables

Sat Dec 12, 2020 10:20 am

Hi
We have a CCR1072 connected to two providers, Cogent and TP. Cogent sends us the full BGP table on a single link. TP splits the network in two seperate links, one for local Bulgaria traffic (coming in on two separate BGP session for failover) and one for International traffic (coming in on two separate BGP sessions for failover). Currently, we see the following:

TP:
Session 1a: BGP Local 7450 routes
Session 1b: BGP Local 7450 routes
Session 2a: BGP Int'l 845000 routes
Session 2b: BGP Int'l 845000 routes

Cogent:
Session 3: BGP Total 858000 routes

If we allow all tables to be pushed to the CCR, we run into a situation with over 2.5 million routes. We are using CCR on 6.47.8. Will switching to ROS v7b3 help us in managing this better?

What is the best way to deploy our network in this situation? Would using a BGP-RR help us and if so, what would be the best way to configure the network? We have looked at filtering /23 or lower routes and use a default route entry for such traffic.

As a note, we have 10 Gbps from Cogent and 3 Gbps from Telepoint (coming in on a 10 Gbps SFP+ interface). Also TP does not limit traffic so we need to keep that under control on our side (if we can)

Would appreciate any help and suggestions extended.
Thanks
 
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StubArea51
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Re: CCR1072 with 2 Provders BGP Full Tables

Sat Dec 12, 2020 4:35 pm

This really depends on what your goals are for maintaining full tables. If you want all traffic to leave via Cogent and only the traffic local to Bulgaria to be sent to the local provider, you can take a default route from Cogent and then learn the ~7000 local routes over the other provider.

If you are selling transit to customers and need the full table, then a route reflector in a VM is ideal. I would recommend Free Range Routing for this task.

Here is an example of this design from a presentation I did at the US MUM in 2019

https://mum.mikrotik.com/presentations/ ... 447941.pdf

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manzur
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Re: CCR1072 with 2 Provders BGP Full Tables

Sat Dec 12, 2020 6:05 pm

Thanks IPANetEngineer
Quick questions:

We need to transit customers so we need full tables.

a) I've been through this and all your other presentations and have had great benefits from them. What do you suggest about moving onto the beta v7 or keep running 6.47.8 with a route reflector?
b) Should we leave all three tables at full without any filters and pull all the tables from all three (2 TP + 1 Cogent) sessions?
c) Not having used BGP too much, if we put in the FRR as the route reflector, I read https://mum.mikrotik.com/presentations/ ... 881037.pdf and it states that they have clients that use the RR to control how routes are advertised. Is that difficult to achieve?
d) In the mikrotik forum, someone commented to leave the CCR as packet forwarding and use a RR to do traffic routing (they suggested maybe using a CHR to do the RR part). How can one set up a network like this?
Thank you for your time and appreciate your help
Regards
 
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j2sw
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Re: CCR1072 with 2 Provders BGP Full Tables

Sat Dec 19, 2020 1:30 pm

The biggest question in my mind. Do you think v7 is stable enough for your production environment? V7 is awesome, just not sure if I would put it into production yet.
 
manzur
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Re: CCR1072 with 2 Provders BGP Full Tables

Sat Dec 19, 2020 2:06 pm

The biggest question in my mind. Do you think v7 is stable enough for your production environment? V7 is awesome, just not sure if I would put it into production yet.
Perfect question. Will await for answers from specialists in the group
 
ste
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Re: CCR1072 with 2 Provders BGP Full Tables

Sat Dec 19, 2020 3:17 pm

The biggest question in my mind. Do you think v7 is stable enough for your production environment? V7 is awesome, just not sure if I would put it into production yet.
This question is rhetoric. ***NO***!!
 
MikrotikBGSHOP
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Re: CCR1072 with 2 Provders BGP Full Tables

Wed Jan 13, 2021 5:56 pm

We are in similar situation, but with HE, TH .
- 2 bgp session for BG and INT(full table) traffic from TH
- 1 full bgp session with from HE

Our border router is ccr1036 and it handles well with couple of million routes in routing table. Well it takes time (more than you would like to) to refresh routes but this matters when bgp sessions flap frequently.

I will suggest definitely to use filters. Routing decisions taken from the router are not always the best decisions. In some cases your traffic to Bulgaria will go trough Cogent and the destination may treat it as international traffic and apply special policies to it.
TH/TP has quite good peering for all BG traffic and applying filters that will push local traffic there has been proved to be good solution for us.
Also with filters you may "engineer" your traffic. F.e you may put some traffic international traffic via cogent and other via TP.
In some of our cases we had to use longer AS path but with lower latency.By default router will choose route with shorter AS path. Filters are also mandatory in order to prevent receiving private networks form upstream providers according to RFC1918 and networks with network mask less than 24.

As for the v7 - it is far from stable and for production it is not recommended at all.

Regards
 
manzur
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Re: CCR1072 with 2 Provders BGP Full Tables

Wed Jan 13, 2021 6:14 pm

We are in similar situation, but with HE, TH .
- 2 bgp session for BG and INT(full table) traffic from TH
- 1 full bgp session with from HE

Our border router is ccr1036 and it handles well with couple of million routes in routing table. Well it takes time (more than you would like to) to refresh routes but this matters when bgp sessions flap frequently.

I will suggest definitely to use filters. Routing decisions taken from the router are not always the best decisions. In some cases your traffic to Bulgaria will go trough Cogent and the destination may treat it as international traffic and apply special policies to it.
TH/TP has quite good peering for all BG traffic and applying filters that will push local traffic there has been proved to be good solution for us.
Also with filters you may "engineer" your traffic. F.e you may put some traffic international traffic via cogent and other via TP.
In some of our cases we had to use longer AS path but with lower latency.By default router will choose route with shorter AS path. Filters are also mandatory in order to prevent receiving private networks form upstream providers according to RFC1918 and networks with network mask less than 24.

As for the v7 - it is far from stable and for production it is not recommended at all.

Regards
Thanks for your input. We are currently also handling the traffic path using filters. We send all local BG traffic via TH BG session. We engineer traffic the same way you have stated and was thinking if we overlooked some "better" way if possible for our requirements.

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