bgp router-id
Configures a BGP router ID.
Syntax: [no] bgp router-id id-number
id-number | IP address that identifies this BGP router. |
Description: Router ID is the tie-breaker for BGP path selection. The path selection process uses a variety of metrics to select a route. If all other metrics (accessibility, administrative weight, local preference, etc.) are equal, BGP determines the router ID using the following priority:
- Use the address configured by the bgp router-id command
- Use the Loopback interface address with the highest IP address
- Use the highest IP address of the interface
- If no interface exists, set the router-ID to 0.0.0.0
Use bgp router-id command to set the router-ID for the system.
WARNING The bgp router-id command causes the BGP and OSPF processes to restart using the new router-ID (if the processes are enabled and router-ID has changed).
Use the no bgp router-id to use the default BGP router-ID for this router.
BGP recomputes the router-ID based on the items 2, 3, and 4 above and restart OSPF and BGP (if they are enabled and router-ID has changed).
Factory Default: Loopback interface with the highest IP address.
Command Mode: Router configuration.
Example: In the following example, the bgp router-id command manually configures the router ID as 5.1.1.49, and the show ip bgp summary command displays the setting:
| router(config-router)#bgp router-id 5.1.1.49 router(config-router)#endrouter#show ip bgp summaryBGP currently operating: AS: 100 Router ID: 5.1.1.49... |
Related Commands: router bgp
show ip bgp summary
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Avici® and TSR® is a registered trademark of Avici Systems Inc.
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Source File Name: BGP_Nd.fm
HTML File Name: BGP_Nd12.html
Last Updated: 05/10/04 at 16:36:55
FAQs
A router ID is the unique identifier of a BGP router in an AS. To ensure the uniqueness of a router ID and enhance network reliability, you can specify in BGP configuration context the IP address of a local loopback interface as the router ID. If no router ID is specified in BGP context, the global router ID is used.
How to select BGP router ID? ›
bgp router-id
- Use the address configured by the bgp router-id command.
- Use the Loopback interface address with the highest IP address.
- Use the highest IP address of the interface.
- If no interface exists, set the router-ID to 0.0. 0.0.
If there is no OSPF Router ID configured, the highest IP address on any of the Routers Loopback Interfaces is selected as the OSPF Router ID. If there is no Loopback Interfaces configured, the highest IP address on its active interfaces is selected as the OSPF Router ID.
How do I verify my BGP route? ›
Verifying the BGP Configuration
- In the Network Operations app, set the filter to Global or a group containing at least one Branch Gateway.
- Under Manage, click Devices > Gateways. A list of gateways is displayed in the List view.
- Click a gateway under Device Name. ...
- Under Manage, click Overview > Routing > BGP.
Each OSPF router selects a router ID (RID) that has to be unique on your network. OSPF stores the topology of the network in its LSDB (Link State Database) and each router is identified with its unique router ID , if you have duplicate router IDs then you will run into reachability issues.
What is the significance of router ID? ›
OSPF uses what's known as a Router ID to identify each router participating in OSPF. The Router ID is a 32-bit field, often represented using dotted decimal notation. This makes the Router ID look like an IP address, but it isn't actually an IP address, just an identifier.
Which criteria is preferred by the router to choose a router ID? ›
The preferred order of criteria for Cisco routers to identify the router ID is: an explicitly configured router using the router-id rid command; the IP address of any configured loopback interface; and the IP address of any active interface on the router (it does not have to be an OSPF-enabled interface).
How to configure BGP in router? ›
BGP router configuration requires the following components:
- BGP Session Parameters: BGP session parameters provide settings that involve establishing communication to the remote BGP neighbor. ...
- Address-Family Initialization: The address-family is initialized under the BGP router configuration mode.
We Love Oranges AS Oranges Mean Pure Refreshment.
- Weight (Highest is Better)
- LOCAL_PREF (Highest is Better)
- Originated Locally.
- AS_PATH (Shortest Wins)
- ORIGIN Type (IGP is Lower than EGP and EGP is Lower than Incomplete)
- MED (Lowest is Better)
- Paths (External > Internal)
- RID (Router ID – Lowest is Better)
Under RFC 6286 rules connecting two routers with the same router ID and different AS numbers is acceptable, while connecting two routers with the same router ID and the same AS number is an error.
To set the router-id, use the command ospf router-id <ip-address> in your OSPF configuration. If your Firebox has multi-WAN enabled, you can configure a loopback interface, and use the IP address of the loopback interface instead of the IP address of the physical interfaces in the dynamic routing configuration.
How can I find my router ID? ›
How to find a router IP address on Windows with the Command Prompt
- Type “CMD” in your search bar and select “Command Prompt.”
- Type “ipconfig.”
- You should see your router's IP address under “Default Gateway.”
Router ID. Prefer the path with the lowest BGP neighbor router ID. The router ID is based on the highest IP address. If you have a loopback interface, the IP address on the loopback will be used.
How do I find my BGP best path? ›
BGP Path Selection
- Verify that the next hop can be resolved.
- Choose the path with the lowest preference value (routing protocol process preference). ...
- Prefer the path with higher local preference.
- If the accumulated interior gateway protocol (AIGP) attribute is enabled, prefer the path with the lower AIGP attribute.
An AS-number must be obtained (leased) from one of the Regional Internet Registries (RIR's) [ARIN, LACNIC, RIPE NCC, AFRINIC, APNIC], but the RIR's receive their blocks of ASN from IANA.
Does OSPF router ID need to match? ›
The RID must be unique within the OSPF network, as a RID provides a point of origin for link state advertisem*nts (LSAs). If LSAs from more than one device improperly sharing a RID appear in the OSPF database, the shortest path first (SPF) calculation for the OSPF area will be, at best, wonky.
Which router support BGP? ›
Cisco Systems has an extensive line of routers that run Cisco's IOS software. The 2500 and higher models support BGP, although the 2500 series itself is not powerfull enough to handle anything near the full routing table. There are now also several multilayer switches such as the 6500 that can route IP and run BGP.
What are the mandatory attributes of BGP? ›
BGP Attribute Categories
Well-known mandatory attributes include:- Next-hop- Origin- AS PATH. Well-known discretionary:Recognized by all routers, passed to all peers, and optionally included in the Update message. Well-known discretionary attributes include:- Local Preference- Atomic Aggregate.
