AS Path
The AS path is the list of all ASs that all the prefixes listed in the update have passed through.
The local AS number is added by the BGP speaker when advertising to a eBGP neighbor.
NOTE:
Any update that contains the AS path number 0 is valid.
The AS path is shown in the following example. The origin attribute is shown following the AS path information (shown in bold).
Example of Viewing AS Paths
Dell#show ip bgp paths
Total 30655 Paths
Address Hash Refcount Metric
Path
0x4014154 0 3 18508
701 3549 19421 i
0x4013914 0 3 18508
701 7018 14990 i
0x5166d6c 0 3 18508
209 4637 1221 9249 9249 i
0x5e62df4 0 2 18508
701 17302 i
0x3a1814c 0 26 18508
209 22291 i
0x567ea9c 0 75 18508
209 3356 2529 i
0x6cc1294 0 2 18508
209 1239 19265 i
0x6cc18d4 0 1 18508
701 2914 4713 17935 i
0x5982e44 0 162 18508
209 i
0x67d4a14 0 2 18508
701 19878 ?
0x559972c 0 31 18508
209 18756 i
0x59cd3b4 0 2 18508
209 7018 15227 i
0x7128114 0 10 18508
209 3356 13845 i
0x536a914 0 3 18508
209 701 6347 7781 i
0x2ffe884 0 1 18508
701 3561 9116 21350 i
Next Hop
The next hop is the IP address used to reach the advertising router.
For EBGP neighbors, the next-hop address is the IP address of the connection between the neighbors. For IBGP, the EBGP next-hop
address is carried into the local AS. A next hop attribute is set when a BGP speaker advertises itself to another BGP speaker outside its
local AS and when advertising routes within an AS. The next hop attribute also serves as a way to direct traffic to another BGP speaker,
rather than waiting for a speaker to advertise. When a next-hop BGP neighbor is unreachable, then the connection to that BGP neighbor
goes down after hold down timer expiry. The connection flap can also be obtained immediately with Fallover enabled. BGP routes that
contain the next-hop as the neighbor address are not sent to the neighbor. You can enable this feature using the
neighbor sender-
side-loopdetect
command.
NOTE:
For EBGP neighbors, the next-hop address corresponding to a BGP route is not resolved if the next-hop address is not
the same as the neighbor IP address.
NOTE:
The connection between a router and its next-hop BGP neighbor terminates immediately only if the router has received
routes from the BGP neighbor in the past.
Multiprotocol BGP
Multiprotocol extensions for BGP (MBGP) is defined in IETF RFC 2858. MBGP allows different types of address families to be distributed in
parallel.
MBGP allows information about the topology of the IP multicast-capable routers to be exchanged separately from the topology of normal
IPv4 and IPv6 unicast routers. It allows a multicast routing topology different from the unicast routing topology.
176
Border Gateway Protocol IPv4 (BGPv4)
Содержание S3048-ON
Страница 1: ...Dell Configuration Guide for the S3048 ON System 9 11 2 5 ...
Страница 137: ...0 Gi 1 1 Gi 1 2 rx Flow N A N A 0 0 No N A N A yes Access Control Lists ACLs 137 ...
Страница 142: ...Figure 10 BFD Three Way Handshake State Changes 142 Bidirectional Forwarding Detection BFD ...
Страница 241: ...Dell Control Plane Policing CoPP 241 ...
Страница 287: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 287 ...
Страница 428: ...Figure 53 Inspecting the LAG Configuration 428 Link Aggregation Control Protocol LACP ...
Страница 429: ...Figure 54 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 429 ...
Страница 432: ...Figure 56 Inspecting a LAG Port on BRAVO Using the show interface Command 432 Link Aggregation Control Protocol LACP ...
Страница 433: ...Figure 57 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 433 ...
Страница 477: ...Figure 73 Configuring Interfaces for MSDP Multicast Source Discovery Protocol MSDP 477 ...
Страница 478: ...Figure 74 Configuring OSPF and BGP for MSDP 478 Multicast Source Discovery Protocol MSDP ...
Страница 479: ...Figure 75 Configuring PIM in Multiple Routing Domains Multicast Source Discovery Protocol MSDP 479 ...
Страница 483: ...Figure 77 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 483 ...
Страница 484: ...Figure 78 MSDP Default Peer Scenario 3 484 Multicast Source Discovery Protocol MSDP ...
Страница 634: ...protocol spanning tree pvst no disable vlan 300 bridge priority 4096 634 Per VLAN Spanning Tree Plus PVST ...
Страница 745: ...Figure 104 Single and Double Tag TPID Match Service Provider Bridging 745 ...
Страница 746: ...Figure 105 Single and Double Tag First byte TPID Match 746 Service Provider Bridging ...