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NOTE: The path-count parameter controls the number of paths that are advertised, not the number of paths that
are received.
DellEMC# configure terminal
DellEMC(conf)# router bgp 400
DellEMC(conf-router_bgp)# neighbor 10.10.10.1 remote-as 500
DellEMC(conf-router_bgp)# bgp add-path both 2
DellEMC(conf-router_bgp)# address-family ipv4 multicast
DellEMC(conf-router_bgp_af)# neighbor 10.10.10.1 activate
DellEMC(conf-router_bgp_af)# neighbor 10.10.10.1 add-path both 3
DellEMC(conf-router_bgp_af)# exit
The above configuration example shows how to enable BGP additional paths to be sent and received with a maximum of
two additional paths to the peers. You can configure the neighbor to send and receive additional paths using the neighbor
add-pathcommand at the address family configuration level.
Configuring IP Community Lists
Within Dell EMC Networking OS, you have multiple methods of manipulating routing attributes.
One attribute you can manipulate is the COMMUNITY attribute. This attribute is an optional attribute that is defined for a group
of destinations. In Dell EMC Networking OS, 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.
Dell EMC Networking OS also supports BGP Extended Communities as described in RFC 4360 — BGP Extended Communities
Attribute.
To configure an IP community list, use these commands.
1. Create a community list and enter COMMUNITY-LIST mode.
CONFIGURATION mode
ip community-list community-list-name
2. Configure a community list by denying or permitting specific community numbers or types of community.
CONFIG-COMMUNITYLIST mode
{deny | permit} {community-number | local-AS | no-advertise | no-export | quote-regexp
regular-expression-list | regexp regular-expression}
● community-number: use AA:NN format where AA is the AS number (2 Bytes or 4 Bytes) and NN is a value specific to
that autonomous system.
● local-AS: routes with the COMMUNITY attribute of NO_EXPORT_SUBCONFED.
● no-advertise: routes with the COMMUNITY attribute of NO_ADVERTISE.
● no-export: routes with the COMMUNITY attribute of NO_EXPORT.
● quote-regexp: then any number of regular expressions. The software applies all regular expressions in the list.
● regexp: then a regular expression.
To view the configuration, use the show config command in CONFIGURATION COMMUNITY-LIST or CONFIGURATION
EXTCOMMUNITY LIST mode or the show ip {community-lists | extcommunity-list} command in EXEC Privilege
mode.
DellEMC#show ip community-lists
ip community-list standard 1
deny 701:20
deny 702:20
Border Gateway Protocol (BGP)
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