Configuring Ip Community Lists - Dell C9000 Series Networking Configuration Manual

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To allow multiple paths sent to peers, use the following commands.

Allow the advertisement of multiple paths for the same address prefix without the new paths replacing

any previous ones.

CONFIG-ROUTER-BGP mode

bgp add-path {send | both} path-count count bgp add-path receive

The range is from 2 to 64.

Allow the specified neighbor/peer group to send/ receive multiple path advertisements.

CONFIG-ROUTER-BGP mode

neighbor {ipaddress| peergroup name} add-path [send | receive| both] path-count

The path-count parameter controls the number of paths that are advertised, not the number of

paths that are received.

Configuring IP Community Lists

Mmultiple methods of manipulating routing attributes are supported in the Dell Networking OS.

One attribute you can manipulate is the COMMUNITY attribute. This attribute is an optional attribute that is

defined for a group of destinations. You can assign a COMMUNITY attribute to BGP routers by using an IP

community list. After you create an IP community list, you can apply routing decisions to all routers meeting

the criteria in the IP community list.

IETF RFC 1997 defines the COMMUNITY attribute and the predefined communities of INTERNET,

NO_EXPORT_SUBCONFED, NO_ADVERTISE, and NO_EXPORT. All BGP routes belong to the INTERNET

community. In the RFC, the other communities are defined as follows:

All routes with the NO_EXPORT_SUBCONFED (0xFFFFFF03) community attribute are not sent to

CONFED-EBGP or EBGP peers, but are sent to IBGP peers within CONFED-SUB-AS.

All routes with the NO_ADVERTISE (0xFFFFFF02) community attribute must not be advertised.

All routes with the NO_EXPORT (0xFFFFFF01) community attribute must not be advertised outside a

BGP confederation boundary, but are sent to CONFED-EBGP and IBGP peers.

The system also supports BGP Extended Communities as described in RFC 4360 — BGP Extended

Communities Attribute.

To configure an IP community list, use these commands.

Create a community list and enter COMMUNITY-LIST mode.

CONFIGURATION mode

ip community-list community-list-name

Configure a community list by denying or permitting specific community numbers or types of

CONFIG-COMMUNITYLIST mode

{deny | permit} {community-number | local-AS | no-advertise | no-export |

quote-regexp regular-expression-list | regexp regular-expression}

Border Gateway Protocol IPv4 (BGPv4)