bgp的問題

stl911

我想知道為什么在實(shí)施bgp的過程中還需要使用ibgp。
我覺得在一個(gè)as內(nèi)部可以運(yùn)行ospf rip等igp協(xié)議
然后把這些igp協(xié)議用ebgp的方法通告給bgp就好了，這樣bgp不也就知道我as內(nèi)部的路由了嗎

blue_sky

看起來好象可行,不知試起來怎么樣,只是你這樣一個(gè)路由器就有一個(gè)以上的AS了,它既是IBGP,又是EBGP,可能對(duì)路由更新,聚合有點(diǎn)影響.

stl911

樓上這位兄弟能不能再說清楚一點(diǎn)，對(duì)于“只是你這樣一個(gè)路由器就有一個(gè)以上的AS了,它既是IBGP,又是EBGP,可能對(duì)路由更新,聚合有點(diǎn)影響.”這句

blue_sky

自己看資料吧,搞清IBGP與EBGP的區(qū)別,及路由更新有什么不同.

yuhong

iBGP describes the peering between BGP neighbors in the same autonomous system(AS). You
use iBGP in transit autonomous systems. Transit autonomous systems forward traffic from one
AS to another AS. If you do not use iBGP in transit autonomous systems, the eBGP learned
routes are redistributed into an IGP and then redistributed into the BGP process in another
eBGP router. iBGP provides a better way to control the routes for the transit AS. With iBGP,
the external route information (attributes) are forwarded. iBGP is preferred over redistribution
with an IGP because the IGP does not understand AS paths and other BGP attributes.
Another use for iBGP is in large corporations where the IGP networks are too large to be supported
by an IGP, such as Open Shortest Path First (OSPF). Three independent IGPs are in
Figure 9-2: one for the Americas; one for Asia and Australia; and one for Europe, the Middle
East, and Africa. Routes are redistributed into an iBGP core.