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amt
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ospf summarization help

Thu Nov 29, 2018 5:01 pm

Hi ,

I need an help to configure network correcly, I divided my ospf network to areas and now I cant summarize the ip blocks with ospf area ranges. I divided one area to 4 different area due to too much router were at one area, these four diffirent area using the ranges 172.17.41.0/24 and 172.17.42.0/24 mixed. how can I summarize them on router B and decrease route table on backbone routers. I try to show with simple diagram at below, Thanks everyone to all helps.

Area Diagram.jpg
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amt
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Re: ospf summarization help

Fri Nov 30, 2018 10:37 pm

no any help ?
 
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sri2007
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Re: ospf summarization help

Sat Dec 01, 2018 5:44 pm

HI! if you're trying to summarize routes using OSPF, then the PPPoE server will be the ABR (area border router) or ASBR; but you'll need to standardize your subnets, as example PPPoE 1 will have clients at only one range (a.e. 172.16.0.0/24); then you can do a redistribute connected and the add a summary network which contains all of the /32 IPs assigned to each CPE.
 
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amt
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Re: ospf summarization help

Sat Dec 01, 2018 8:35 pm

HI! if you're trying to summarize routes using OSPF, then the PPPoE server will be the ABR (area border router) or ASBR; but you'll need to standardize your subnets, as example PPPoE 1 will have clients at only one range (a.e. 172.16.0.0/24); then you can do a redistribute connected and the add a summary network which contains all of the /32 IPs assigned to each CPE.
Hi sri2007,
thanks for your help, I can summarize pppoe_server pool on pppoe server, but I need summarize these area's ip blocks on router B.
 
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sri2007
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Re: ospf summarization help

Sat Dec 01, 2018 10:28 pm

ohh, ok got it... so the main question here will be, does the router B have interfaces assigned to each area (I mean area 0, area 1 and area 2); or only each PowerBox has one interface at the backbone area and the other one in the default area?

The rule is that only the ABR (area border router) or the ASBR (autonomous system border router) are allowed to summarize (aggregate) networks.
 
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amt
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Re: ospf summarization help

Sat Dec 01, 2018 11:14 pm

ohh, ok got it... so the main question here will be, does the router B have interfaces assigned to each area (I mean area 0, area 1 and area 2); or only each PowerBox has one interface at the backbone area and the other one in the default area?

The rule is that only the ABR (area border router) or the ASBR (autonomous system border router) are allowed to summarize (aggregate) networks.
yes router B have area 1,area 2 and area3 on it... and router B also at Backbone area...

Thanks
 
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amt
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Re: ospf summarization help

Mon Dec 03, 2018 4:58 pm

any update ?
 
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amt
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Re: ospf summarization help

Tue Dec 04, 2018 11:34 pm

no answer ?
 
mducharme
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Re: ospf summarization help

Fri Dec 07, 2018 2:56 am

Hi amt, you use an "area range" on router B to summarize the area to other areas. You can create it under Routing->OSPF->Area Ranges.
 
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Re: ospf summarization help

Fri Dec 07, 2018 8:16 am

Hi amt, you use an "area range" on router B to summarize the area to other areas. You can create it under Routing->OSPF->Area Ranges.
hi mducharme,
thanks for your answer... it was like as you said, I was using area range to summarize but it was one area before and I used 3 x /24 ip range at this one area, now I divided that area to 3 diffrend area and all ip's mixed on area's now thats why I cant use that code below;
add area=area1  range=172.17.30.0/24
because ip address 172.17.30.1/29 at area1 but 172.17.30.9/30 at area2 and 172.17.30.21/30 at area3
I divided one are to 3 different area because there were 160 device on one area and I thought that may create problem for ospf. how many device can be in one area ?

Thanks
 
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Re: ospf summarization help

Fri Dec 07, 2018 9:36 am

If the public IP ranges are mixed randomly in all areas, one solution can be to tunnel the customers back to a central router (or routers) using either VPLS tunnels (preferred) or EoIP tunnels. That central router (or routers) can then have an OSPF stub area with an area range to summarize the advertisements.

Why do you have so many OSPF routers - is each AP on your network doing OSPF as well? We only do OSPF on the site head end router (where your powerbox seems to sit) instead of on each AP. Our AP's are bridged.
 
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amt
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Re: ospf summarization help

Fri Dec 07, 2018 10:28 am

If the public IP ranges are mixed randomly in all areas, one solution can be to tunnel the customers back to a central router (or routers) using either VPLS tunnels (preferred) or EoIP tunnels. That central router (or routers) can then have an OSPF stub area with an area range to summarize the advertisements.
no any puplic ip, puplic ip's only on pppoe server...
Why do you have so many OSPF routers - is each AP on your network doing OSPF as well? We only do OSPF on the site head end router (where your powerbox seems to sit) instead of on each AP. Our AP's are bridged.
Only PowerBox work ospf, AP's are connected with /30 ip to powerbox and I add /30 ip to ospf networks on PowerBox so I can reach to the AP's.. is this way wrong ?

and How many device can I use in one area ? if 160- 170 device not problem I can collect them again to one area.
 
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Re: ospf summarization help

Fri Dec 07, 2018 10:53 pm

Please explain what you mean by 160-170 "devices". Do you mean 160-170 OSPF routers (ex. 160 powerboxes)?
 
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amt
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Re: ospf summarization help

Fri Dec 07, 2018 11:23 pm

Please explain what you mean by 160-170 "devices". Do you mean 160-170 OSPF routers (ex. 160 powerboxes)?
160 device but ospf not working all of them, for example p2p links connected with /29 , AP's with connected to powerbox with /30. Only power box or Rb1100 works with ospf if AP attached on it or if any p2p link
 
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Re: ospf summarization help

Fri Dec 07, 2018 11:40 pm

160 device but ospf not working all of them, for example p2p links connected with /29 , AP's with connected to powerbox with /30. Only power box or Rb1100 works with ospf if AP attached on it or if any p2p link
Then how many OSPF routers and how many routes?
 
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amt
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Re: ospf summarization help

Sat Dec 08, 2018 9:42 am

Then how many OSPF routers and how many routes?
60 ospf installed router and 100 not installed(which is AP or P2p Link)
 
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Re: ospf summarization help

Sat Dec 08, 2018 10:06 am

60 ospf installed router and 100 not installed(which is AP or P2p Link)
But how many OSPF routes in the routing table? My thought is you probably do not need so many areas, especially if you only have a couple hundred routes. More areas used to be needed with older routers, but those were recommendations based on 1990's or early 2000's routers.
 
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amt
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Re: ospf summarization help

Mon Dec 10, 2018 10:22 am

But how many OSPF routes in the routing table? My thought is you probably do not need so many areas, especially if you only have a couple hundred routes. More areas used to be needed with older routers, but those were recommendations based on 1990's or early 2000's routers.
Sorry I missed that you asked for routes, Area1 60 routes, Area2 33 routes, Area3 44 Routes if i collect them in one area total routes will be 137. too much or its very low for one area ?

I also try to create black hole route and redistribute the static route on router B to make summarize but couldn't success.

Thanks for your all help
 
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Re: ospf summarization help

Mon Dec 10, 2018 7:41 pm

Sorry I missed that you asked for routes, Area1 60 routes, Area2 33 routes, Area3 44 Routes if i collect them in one area total routes will be 137. too much or its very low for one area ?
That is fine for one area, you don't need three. It especially doesn't make sense to split things into different areas if you do not have the subnets arranged in such a way that you can summarize properly, which is what it seems you had done.
 
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amt
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Re: ospf summarization help

Tue Dec 11, 2018 11:05 am

Sorry I missed that you asked for routes, Area1 60 routes, Area2 33 routes, Area3 44 Routes if i collect them in one area total routes will be 137. too much or its very low for one area ?
That is fine for one area, you don't need three. It especially doesn't make sense to split things into different areas if you do not have the subnets arranged in such a way that you can summarize properly, which is what it seems you had done.
so, I understand that you suggest me to convert multiple area to 1 area back and do summarize with area ranges.

and I understand that there is no any summarize choice if multiple subnets used at multiple areas
 
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Re: ospf summarization help  [SOLVED]

Tue Dec 11, 2018 11:16 am

so, I understand that you suggest me to convert multiple area to 1 area back and do summarize with area ranges.

and I understand that there is no any summarize choice if multiple subnets used at multiple areas
Correct, for both.

If you want to have more areas, renumber your networks so that they can be easily summarized with area ranges. However, I don't think it is that necessary with the small areas you describe. OSPF areas are helpful once you start having several hundred routes, or for things like PPPoE Tunnels where LSA updates are frequent due to tunnel up/down. In most cases with a reasonably stable network you can have a few hundred routes or even more with no problem with one area. If you had ~400 routes or more, then I might suggest renumbering to improve the ability to summarize them.
 
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amt
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Re: ospf summarization help

Tue Dec 11, 2018 2:25 pm

Correct, for both.

If you want to have more areas, renumber your networks so that they can be easily summarized with area ranges. However, I don't think it is that necessary with the small areas you describe. OSPF areas are helpful once you start having several hundred routes, or for things like PPPoE Tunnels where LSA updates are frequent due to tunnel up/down. In most cases with a reasonably stable network you can have a few hundred routes or even more with no problem with one area. If you had ~400 routes or more, then I might suggest renumbering to improve the ability to summarize them.
Thank you mducharme,
thanks for giving a time for me and explain... I will care route number and when it will nearly more then 300 routes on ospf router I will create new area. now Im going to back one area and summarize network. thanks again.

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