Cabletron Systems SSIM-R8-02 Specifikace stáhnout pdf (Strana 190)

BGP Configuration Examples

170 Enterasys Xpedition User Reference Manual

The specific community consists of the combination of the AS-value and community

ID.

• Well-known-community no-export

Well-known-community no-export is a special community which indicates that the

routes associated with this attribute must not be advertised outside a BGP

confederation boundary. Since the XP’s implementation does not support

Confederations, this boundary is an AS boundary.

For example, router XP10 in Figure 14 has the following configuration:

• Well-known-community no-advertise

Well-known-community no-advertise is a special community indicating that the routes

associated with this attribute must not be advertised to other /jointfilesconvert/276250/bgp peers. A packet can

be modified to contain this attribute and passed to its neighbor. However, if a packet

is received with this attribute, it cannot be transmitted to another BGP peer.

• Well-known-community no-export-subconfed

Well-known-community no-export-subconfed is a special community indicating the

routes associated with this attribute must not be advertised to external BGP peers.

(This includes peers in other members’ autonomous systems inside a BGP

confederation.)

A packet can be modified to contain this attribute and passed to its neighbor. However,

if a packet is received with this attribute, the routes (prefix-attribute pair) cannot be

advertised to an external BGP peer.

• Well-known-community none

This is not actually a community, but rather a keyword that specifies that a received

BGP update is only to be matched if no communities are present. It has no effect when

originating communities.

Notes on Using Communities

When originating BGP communities, the set of communities that is actually sent is the

union of the communities received with the route (if any), those specified in group policy

(if any), and those specified in export policy (if any).

When receiving BGP communities, the update is only matched if all communities

specified in the optional-attributes-list option of the ip-router policy create command are

present in the BGP update. (If additional communities are also present in the update, it

will still be matched.)

ip-router policy create optional-attributes-list noexport well-known-community no-export

ip-router policy create /jointfilesconvert/276250/bgp-export-destination 900to901dest autonomous-system 64901 optional-attributes-

list noexport

ip-router policy export destination 900to901dest source 900to901src network all

ip-router policy export destination 900to901dest source 900to901dir network all

1 2 ... 185 186 187 188 189 190 191 192 193 194 195 ... 393 394

Žádné komentáře

Cabletron Systems SSIM-R8-02 Specifikace Strana 190