connect in two places. Each connection is a BGP session. AS200 sets the MED for its T1 exit point to 100
and the MED for its OC3 exit point to 50. This sets up a path preference through the OC3 link. The MEDs
are advertised to AS100 routers so they know which is the preferred path.
MEDs are non-transitive attributes. If AS100 sends an MED to AS200, AS200 does not pass it on to AS300
or AS400. The MED is a locally relevant attribute to the two participating ASs (AS100 and AS200).
NOTE: The MEDs are advertised across both links, so if a link goes down, AS 1 still has connectivity
to AS300 and AS400.
Figure 26. Multi-Exit Discriminators
NOTE: Configuring the
set metric-type internal
command in a route-map advertises the
IGP cost as MED to outbound EBGP peers when redistributing routes. The configured
set metric
value overwrites the default IGP cost. If the outbound route-map uses MED, it overwrites IGP MED.
Origin
The origin indicates the origin of the prefix, or how the prefix came into BGP. There are three origin
codes: IGP, EGP, INCOMPLETE.
Origin Type
Description
IGP
Indicates the prefix originated from information learned through an interior
gateway protocol.
EGP
Indicates the prefix originated from information learned from an EGP protocol,
which NGP replaced.
INCOMPLETE
Indicates that the prefix originated from an unknown source.
Generally, an IGP indicator means that the route was derived inside the originating AS. EGP generally
means that a route was learned from an external gateway protocol. An INCOMPLETE origin code
generally results from aggregation, redistribution, or other indirect ways of installing routes into BGP.
206
Border Gateway Protocol IPv4 (BGPv4)
Содержание S4820T
Страница 1: ...Dell Configuration Guide for the S4820T System 9 8 0 0 ...
Страница 282: ...Dell 282 Control Plane Policing CoPP ...
Страница 569: ...Figure 62 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 569 ...
Страница 572: ...Figure 64 Inspecting a LAG Port on BRAVO Using the show interface Command 572 Link Aggregation Control Protocol LACP ...
Страница 573: ...Figure 65 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 573 ...
Страница 617: ...mac address table static multicast mac address vlan vlan id output range interface Microsoft Network Load Balancing 617 ...
Страница 622: ...Figure 81 Configuring Interfaces for MSDP 622 Multicast Source Discovery Protocol MSDP ...
Страница 623: ...Figure 82 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 623 ...
Страница 624: ...Figure 83 Configuring PIM in Multiple Routing Domains 624 Multicast Source Discovery Protocol MSDP ...
Страница 629: ...Figure 86 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 629 ...
Страница 630: ...Figure 87 MSDP Default Peer Scenario 3 630 Multicast Source Discovery Protocol MSDP ...
Страница 751: ...10 11 5 2 00 00 05 00 02 04 Member Ports Te 1 2 1 PIM Source Specific Mode PIM SSM 751 ...
Страница 905: ...Figure 112 Single and Double Tag First byte TPID Match Service Provider Bridging 905 ...
Страница 979: ...6 Member not present 7 Member not present Stacking 979 ...
Страница 981: ...storm control Storm Control 981 ...
Страница 999: ... Te 1 1 0 INCON Root Rootguard Te 1 2 0 LIS Loopguard Te 1 3 0 EDS Shut Bpduguard Spanning Tree Protocol STP 999 ...
Страница 1103: ...Figure 134 Setup OSPF and Static Routes Virtual Routing and Forwarding VRF 1103 ...