The most popular option is option C, the problem with option A is scalability and managment overhead. However, implementing option B and option C is not trivial, while option A does not need any special handling besides basic MPLS-VPN implementation, so option A is kind of poor man's Inter-AS solution, any vendor that supports basic MPLS-VPN will be able to implement inter-AS by using option A. Of cause, vendor has to support "sub-interface" on ASBR link (vlan on Ethernet, sub-interface on ATM B
nod, and I don't think option A has ever been popular. All 3 options are defined in the same RFC (2547bis then 4364), that means when ppl think of inter-as MPLS VPN, they've known all 3 options. The drawback of option A is very obviously, tho it looks very simple. However, when 2 SP's talking about inter-as vpn connectivity, they normally want some strategy inter- connectivity, not just case by case, which is as you said, not scale, high maintain cost. the problem of option C is it requires 2 SP
【在 s*****g 的大作中提到】 : The most popular option is option C, the problem with option A is : scalability and managment overhead. However, implementing option B and option C is not trivial, while option A does not need any special handling besides basic MPLS-VPN implementation, so option A is kind of poor man's Inter-AS solution, any vendor that supports basic MPLS-VPN will be able to implement inter-AS by using option A. Of cause, vendor has to support "sub-interface" on ASBR link (vlan on Ethernet, sub-interface on ATM B
d*i
4 楼
//hand. I think option B is also easier to implement compared to option C. for example, our testcenter can test this using option b only because we almost don't need to do anything additional to implement this test.
is about route
【在 z**r 的大作中提到】 : nod, and I don't think option A has ever been popular. All 3 options are : defined in the same RFC (2547bis then 4364), that means when ppl think of : inter-as MPLS VPN, they've known all 3 options. The drawback of option A is : very obviously, tho it looks very simple. However, when 2 SP's talking about : inter-as vpn connectivity, they normally want some strategy inter- : connectivity, not just case by case, which is as you said, not scale, high : maintain cost. : the problem of option C is it requires 2 SP
z*r
5 楼
right, option C increases the complexity because of the route reflectors btw, are you still busy everyday? and how was your interview?
for example, our to
【在 d****i 的大作中提到】 : //hand. I think option B is also easier to implement compared to option C. for example, our : testcenter can test this using option b only because we almost don't need to : do anything additional to implement this test. : : is : about : route
p*a
6 楼
option b is not very scalable and has some security concerns.
is about route
【在 z**r 的大作中提到】 : nod, and I don't think option A has ever been popular. All 3 options are : defined in the same RFC (2547bis then 4364), that means when ppl think of : inter-as MPLS VPN, they've known all 3 options. The drawback of option A is : very obviously, tho it looks very simple. However, when 2 SP's talking about : inter-as vpn connectivity, they normally want some strategy inter- : connectivity, not just case by case, which is as you said, not scale, high : maintain cost. : the problem of option C is it requires 2 SP
p*a
7 楼
actually some vendors still don't support option c yet. option c also has some security concerns.
option C is not trivial, while option A does not need any special handling besides basic MPLS-VPN implementation, so option A is kind of poor man's Inter-AS solution, any vendor t
【在 s*****g 的大作中提到】 : The most popular option is option C, the problem with option A is : scalability and managment overhead. However, implementing option B and option C is not trivial, while option A does not need any special handling besides basic MPLS-VPN implementation, so option A is kind of poor man's Inter-AS solution, any vendor that supports basic MPLS-VPN will be able to implement inter-AS by using option A. Of cause, vendor has to support "sub-interface" on ASBR link (vlan on Ethernet, sub-interface on ATM B
s*g
8 楼
Could you please elaborate what are the security concerns of option B and option C? And how are those security concerns are addressed by option A? IPsec over MPLS is always an option if customers are paranoid.
【在 p***a 的大作中提到】 : actually some vendors still don't support option c yet. option c also has : some security concerns. : : option C is not trivial, while option A does not need any special handling : besides basic MPLS-VPN implementation, so option A is kind of poor man's : Inter-AS solution, any vendor t
s*g
9 楼
Of course you don't run IGP between to SPs for option C, this is a basic requriement of any inter-AS, no IGP between ASBRs. Problem with option B is also obvious, ASBRs have to be VPN aware (you need to configure vrf/vpn address family under ASBR's bgp in order to exchange VPN labels with neighbors) and ASBRs have to hold all VPN routes (just imagine if you have a dozen customers and each customer wants to have whole Internet routes ..., not many vendors on the market can do over 1M routes hardw
【在 z**r 的大作中提到】 : nod, and I don't think option A has ever been popular. All 3 options are : defined in the same RFC (2547bis then 4364), that means when ppl think of : inter-as MPLS VPN, they've known all 3 options. The drawback of option A is : very obviously, tho it looks very simple. However, when 2 SP's talking about : inter-as vpn connectivity, they normally want some strategy inter- : connectivity, not just case by case, which is as you said, not scale, high : maintain cost. : the problem of option C is it requires 2 SP
z*r
10 楼
I actually wanted to mean the IGP routes are exchanged between AS's in option C, because an ASBR must have the knowledge of all loopbacks of the PE routers within the AS, then uses eBGP to advertise them to other AS's. This requires greater trust between 2 SP's. Also a lot of situations that ppl use RR to improve the scalability, thus the eBGP connections exist only between the blue RR in the blue AS and the green RR in the green AS. In option B, ASBR VPN awareness shouldn't be a problem at all,
【在 s*****g 的大作中提到】 : Of course you don't run IGP between to SPs for option C, this is a basic : requriement of any inter-AS, no IGP between ASBRs. : Problem with option B is also obvious, ASBRs have to be VPN aware (you need : to configure vrf/vpn address family under ASBR's bgp in order to exchange : VPN labels with neighbors) and ASBRs have to hold all VPN routes (just : imagine if you have a dozen customers and each customer wants to have whole : Internet routes ..., not many vendors on the market can do over 1M routes : hardw
p*a
11 楼
i agree with you more on this. but actually different ASes can be in a singile IGP domain, of course, in this case the ASes should belong to a same provider.
need whole PEs
【在 s*****g 的大作中提到】 : Of course you don't run IGP between to SPs for option C, this is a basic : requriement of any inter-AS, no IGP between ASBRs. : Problem with option B is also obvious, ASBRs have to be VPN aware (you need : to configure vrf/vpn address family under ASBR's bgp in order to exchange : VPN labels with neighbors) and ASBRs have to hold all VPN routes (just : imagine if you have a dozen customers and each customer wants to have whole : Internet routes ..., not many vendors on the market can do over 1M routes : hardw
p*a
12 楼
for option b, the security concern is label spoofing at the asbr for option c, the security concern is access to all PEs from the remote AS yes you can use some tools such as filter to reduce the risk but SPs still should worry about it.
【在 s*****g 的大作中提到】 : Could you please elaborate what are the security concerns of option B and : option C? : And how are those security concerns are addressed by option A? : IPsec over MPLS is always an option if customers are paranoid.