Skip to main content
Sign Out

Welcome to Dell

My Account
  • Place orders quickly and easily
  • View orders and track your shipping status
  • Create and access a list of your products
  • Manage your Dell EMC sites, products, and product-level contacts using Company Administration.
Sign In Create an Account Premier Sign In Partner Program Sign In
Contact Us

Dell PowerEdge FN I/O Module Configuration Guide 9.10(0.0)

PDF

Enabling BGP

By default, BGP is not enabled on the system. The Dell Networking OS supports one autonomous system (AS) and assigns the AS number (ASN).

To establish BGP sessions and route traffic, configure at least one BGP neighbor or peer.

In BGP, routers with an established TCP connection are called neighbors or peers. After a connection is established, the neighbors exchange full BGP routing tables with incremental updates afterward. In addition, neighbors exchange KEEPALIVE messages to maintain the connection.

In BGP, neighbor routers or peers can be classified as external. External BGP peers must be connected physically to one another (unless you enable the EBGP multihop feature), while internal BGP peers do not need to be directly connected. The IP address of an EBGP neighbor is usually the IP address of the interface directly connected to the router. First, the BGP process determines if all internal BGP peers are reachable, then it determines which peers outside the AS are reachable.

  1. Assign an AS number and enter ROUTER BGP mode. CONFIGURATION mode router bgp as-number
    • as-number : from 0 to 65535 (2 Byte) or from 1 to 4294967295 (4 Byte) or 0.1 to 65535.65535 (Dotted format).
    Only one AS is supported per system.
    • NOTE: If you enter a 4-Byte AS number, 4-Byte AS support is enabled automatically.
    1. Enable 4-Byte support for the BGP process.
      • NOTE: This command is OPTIONAL. Enable if you want to use 4-Byte AS numbers or if you support AS4 number representation.
      CONFIG-ROUTER-BGP mode bgp four-octet-as-support
      • NOTE: Use it only if you support 4-Byte AS numbers or if you support AS4 number representation. If you are supporting 4-Byte ASNs, enable this command.
      Disable 4-Byte support and return to the default 2-Byte format by using the no bgp four-octet-as-support command. You cannot disable 4-Byte support if you currently have a 4-Byte ASN configured. Disabling 4-Byte AS numbers also disables ASDOT and ASDOT+ number representation. All AS numbers are displayed in ASPLAIN format.
    2. Enable IPv4 multicast or IPv6 mode. CONFIG-ROUTER-BGP mode address-family [ipv4 | ipv6} Use this command to enter BGP for IPv6 mode (CONF-ROUTER_BGPv6_AF).
  2. Add a neighbor as a remote AS. CONFIG-ROUTER-BGP mode neighbor { ip-address | peer-group name } remote-as as-number
    • peer-group name : 16 characters
    • as-number : from 0 to 65535 (2 Byte) or from 1 to 4294967295 (4 Byte) or 0.1 to 65535.65535 (Dotted format)
    Formats: IP Address A.B.C.D You must use Configuring Peer Groups before assigning them a remote AS.
  3. Enable the BGP neighbor. CONFIG-ROUTER-BGP mode neighbor { ip-address | peer-group-name} no shutdown

Example of the show ip bgp summary Command (2-Byte AS number displayed)

  • NOTE: When you change the configuration of a BGP neighbor, always reset it by entering the clear ip bgp command in EXEC Privilege mode.

To view the BGP configuration, enter show config in CONFIGURATION ROUTER BGP mode. To view the BGP status, use the show ip bgp summary command in EXEC Privilege mode. The first example shows the summary with a 2-byte AS number displayed (in bold); the second example shows that the summary with a 4-byte AS number using the show ip bgp summary command (displays a 4–byte AS number in bold). 

R2#show ip bgp summary
                                 BGP router identifier 192.168.10.2, local 
                                 AS number 65123
                                 BGP table version is 1, main routing table version 1
                                 1 network entrie(s) using 132 bytes of memory
                                 1 paths using 72 bytes of memory
                                 BGP-RIB over all using 73 bytes of memory
                                 1 BGP path attribute entrie(s) using 72 bytes of memory
                                 1 BGP AS-PATH entrie(s) using 47 bytes of memory
                                 5 neighbor(s) using 23520 bytes of memory
                                 
                                 Neighbor     AS    MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
                                 
                                 10.10.21.1   65123 0       0       0      0    0 never    Active
                                 10.10.32.3   65123 0       0       0      0    0 never    Active
                                 
                              
R2#show ip bgp summary
                                 BGP router identifier 192.168.10.2, local 
                                 AS number 48735.59224
                                 BGP table version is 1, main routing table version 1
                                 1 network entrie(s) using 132 bytes of memory
                                 1 paths using 72 bytes of memory
                                 BGP-RIB over all using 73 bytes of memory
                                 1 BGP path attribute entrie(s) using 72 bytes of memory
                                 1 BGP AS-PATH entrie(s) using 47 bytes of memory
                                 5 neighbor(s) using 23520 bytes of memory
                                 
                                 Neighbor     AS    MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
                                 
                                 10.10.21.1   65123 0       0       0      0   0    never   Active
                                 10.10.32.3   65123 0       0       0      0   0    never   Active

For the router’s identifier, the system uses the highest IP address of the Loopback interfaces configured. Because Loopback interfaces are virtual, they cannot go down, thus preventing changes in the router ID. If you do not configure Loopback interfaces, the highest IP address of any interface is used as the router ID.

To view the status of BGP neighbors, use the show ip bgp neighbors command in EXEC Privilege mode as shown in the first example. For BGP neighbor configuration information, use the show running-config bgp command in EXEC Privilege mode as shown in the second example.

  • NOTE: The showconfig command in CONFIGURATION ROUTER BGP mode gives the same information as the show running-config bgp command.

The following example displays two neighbors: one is an external internal BGP neighbor and the second one is an internal BGP neighbor. The first line of the output for each neighbor displays the AS number and states whether the link is an external or internal (shown in bold).

The third line of the show ip bgp neighbors output contains the BGP State. If anything other than ESTABLISHED is listed, the neighbor is not exchanging information and routes. For more information about using the show ip bgp neighbors command, refer to the Dell Networking OS Command Line Interface Reference Guide. 

Dell#show ip bgp neighbors
                                 
                                 
                                 BGP neighbor is 10.114.8.60, remote AS 18508, external link
                                 BGP version 4, remote router ID 10.20.20.20
                                 BGP state ESTABLISHED, in this state for 00:01:58
                                 Last read 00:00:14, hold time is 90, keepalive interval is 30 seconds
                                 Received 18552 messages, 0 notifications, 0 in queue
                                 Sent 11568 messages, 0 notifications, 0 in queue
                                 Received 18549 updates, Sent 11562 updates
                                 Minimum time between advertisement runs is 30 seconds
                                 
                                 For address family: IPv4 Unicast
                                 BGP table version 216613, neighbor version 201190
                                 130195 accepted prefixes consume 520780 bytes
                                 Prefix advertised 49304, rejected 0, withdrawn 36143
                                 
                                 Connections established 1; dropped 0
                                 Last reset never
                                 Local host: 10.114.8.39, Local port: 1037
                                 Foreign host: 10.114.8.60, Foreign port: 179
                                 
                                 
                                 BGP neighbor is 10.1.1.1, remote AS 65535, internal link
                                 Administratively shut down
                                 BGP version 4, remote router ID 10.0.0.0
                                 BGP state IDLE, in this state for 17:12:40
                                 Last read 17:12:40, hold time is 180, keepalive interval is 60 seconds
                                 Received 0 messages, 0 notifications, 0 in queue
                                 Sent 0 messages, 0 notifications, 0 in queue
                                 Received 0 updates, Sent 0 updates
                                 Minimum time between advertisement runs is 5 seconds
                                 
                                 For address family: IPv4 Unicast
                                 BGP table version 0, neighbor version 0
                                 0 accepted prefixes consume 0 bytes
                                 Prefix advertised 0, rejected 0, withdrawn 0
                                 
                                 Connections established 0; dropped 0
                                 Last reset never
                                 No active TCP connection
                                 Dell#
                              
R2#show running-config bgp
                                 !
                                 router bgp 65123
                                 bgp router-id 192.168.10.2
                                 network 10.10.21.0/24
                                 network 10.10.32.0/24
                                 network 100.10.92.0/24
                                 network 192.168.10.0/24
                                 bgp four-octet-as-support
                                 neighbor 10.10.21.1 remote-as 65123
                                 neighbor 10.10.21.1 filter-list ISP1in
                                 neighbor 10.10.21.1 no shutdown
                                 neighbor 10.10.32.3 remote-as 65123
                                 neighbor 10.10.32.3 no shutdown
                                 neighbor 100.10.92.9 remote-as 65192
                                 neighbor 100.10.92.9 no shutdown
                                 neighbor 192.168.10.1 remote-as 65123
                                 neighbor 192.168.10.1 update-source Loopback 0

Rate this content

Accurate
Useful
Easy to understand
Was this article helpful?
0/3000 characters
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please select whether the article was helpful or not.
  Comments cannot contain these special characters: <>()\