MBGP uses either an IPv4 address configured on the interface (which is used to establish the IPv6 session) or a stable IPv4 address that is
available in the box as the next-hop address. As a result, while advertising an IPv6 network, exchange of IPv4 routes does not lead to
martian next-hop message logs.
NOTE:
It is possible to configure BGP peers that exchange both unicast and multicast network layer reachability information
(NLRI), but you cannot connect multiprotocol BGP with BGP. Therefore, you cannot redistribute multiprotocol BGP routes into
BGP.
Implement BGP with Dell Networking OS
The following sections describe how to implement BGP on Dell Networking OS.
Additional Path (Add-Path) Support
The add-path feature reduces convergence times by advertising multiple paths to its peers for the same address prefix without replacing
existing paths with new ones. By default, a BGP speaker advertises only the best path to its peers for a given address prefix. If the best
path becomes unavailable, the BGP speaker withdraws its path from its local RIB and recalculates a new best path. This situation requires
both IGP and BGP convergence and can be a lengthy process. BGP add-path also helps switchover to the next new best path when the
current best path is unavailable.
Advertise IGP Cost as MED for Redistributed Routes
When using multipath connectivity to an external AS, you can advertise the MED value selectively to each peer for redistributed routes. For
some peers you can set the internal/IGP cost as the MED while setting others to a constant pre-defined metric as MED value.
Use the
set metric-type internal
command in a route-map to advertise the IGP cost as the MED to outbound EBGP peers when
redistributing routes. The configured
set metric
value overwrites the default IGP cost.
By using the
redistribute
command with the
route-map
command, you can specify whether a peer advertises the standard MED or
uses the IGP cost as the MED.
When configuring this functionality:
•
If the
redistribute
command does not have
metric
configured and the BGP peer outbound route-map does have
metric-
type internal
configured, BGP advertises the IGP cost as MED.
•
If the
redistribute
command has
metric
configured (
route-map set metric
or
redistribute
route-type
metric
) and the BGP peer outbound route-map has
metric-type internal
configured, BGP advertises the metric configured
in the
redistribute
command as MED.
•
If BGP peer outbound route-map has
metric
configured, all other metrics are overwritten by this configuration.
NOTE:
When redistributing static, connected, or OSPF routes, there is no
metric
option. Simply assign the appropriate route-
map to the redistributed route.
The following table lists some examples of these rules.
Table 10. Redistributed Route Rules
Command Settings
BGP Local Routing Information
Base
MED Advertised to Peer
WITH route-map metric-type
internal
MED Advertised to Peer
WITHOUT route-map metric-
type internal
redistribute isis (IGP cost = 20)
MED: IGP cost 20
MED = 20
MED = 0
redistribute isis route-map set
metric 50
MED: IGP cost 50
MED: 50 MED: 50
MED: 50 MED: 50
redistribute isis metric 100
MED: IGP cost 100
MED: 100
MED: 100
186
Border Gateway Protocol IPv4 (BGPv4)
Содержание S4048T-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 11 2 1 ...
Страница 148: ...Figure 10 BFD Three Way Handshake State Changes 148 Bidirectional Forwarding Detection BFD ...
Страница 251: ...Dell Control Plane Policing CoPP 251 ...
Страница 363: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 363 ...
Страница 511: ...Figure 64 Inspecting the LAG Configuration Link Aggregation Control Protocol LACP 511 ...
Страница 512: ...Figure 65 Inspecting Configuration of LAG 10 on ALPHA 512 Link Aggregation Control Protocol LACP ...
Страница 515: ...Figure 67 Inspecting a LAG Port on BRAVO Using the show interface Command Link Aggregation Control Protocol LACP 515 ...
Страница 516: ...Figure 68 Inspecting LAG 10 Using the show interfaces port channel Command 516 Link Aggregation Control Protocol LACP ...
Страница 558: ...Figure 84 Configuring Interfaces for MSDP 558 Multicast Source Discovery Protocol MSDP ...
Страница 559: ...Figure 85 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 559 ...
Страница 560: ...Figure 86 Configuring PIM in Multiple Routing Domains 560 Multicast Source Discovery Protocol MSDP ...
Страница 564: ...Figure 88 MSDP Default Peer Scenario 2 564 Multicast Source Discovery Protocol MSDP ...
Страница 565: ...Figure 89 MSDP Default Peer Scenario 3 Multicast Source Discovery Protocol MSDP 565 ...
Страница 729: ...protocol spanning tree pvst no disable vlan 300 bridge priority 4096 Per VLAN Spanning Tree Plus PVST 729 ...
Страница 841: ...Figure 115 Single and Double Tag TPID Match Service Provider Bridging 841 ...
Страница 842: ...Figure 116 Single and Double Tag First byte TPID Match 842 Service Provider Bridging ...