Nokia Router 7750 SR BGP Basic configuration

Let's explore few concepts of BGP and how to configure it on the Nokia 7750 SR

Border gateway protocol is mainly used by Service Providers to carry the huge routing information between different Autonomous Systems.

It uses the well-known TCP port number 179. BGP uses TCP protocol for authenticating its peer router session.

There are two types of BGP as listed below

1. IBGP (Internal BGP used to share routing information within its own AS)

2. Ebgp (External BGP used to share routing information between 2 different AS)

Let's explore how to configure BGP types as per the below topology. IGP is pre-configured as per topology.


1. IBGP configuration between PE01 to PE02 

Forming IBGP between Router system IP/Loopback address is a best practice for family ipv4.

why are we configuring internal BGP on SYSTEM/LOOPBACK IP?

If we configure the adjacency using the physical interface for the ipv4 family it will lead to failure if that particular interface goes down.

Even if we have an alternate path to reach the router it will not be useful if we configure it in the physical interface once the interface goes down.

PE01:  10.10.10.1
PE02:  10.10.10.2

PE01:

/configure router bgp autonomous 

/configure router bgp group "ibgp-internal"

/configure router bgp group "ibgp-internal" neighbor 10.10.10.2

/configure router bgp group "ibgp-internal" neighbor 10.10.10.2 type internal

/configure router bgp group "ibgp-internal" neighbor 10.10.10.2 peer-as 65001


PE02:

/configure router bgp autonomous 

/configure router bgp group "ibgp-internal"

/configure router bgp group "ibgp-internal" neighbor 10.10.10.1

/configure router bgp group "ibgp-internal" neighbor 10.10.10.1 type internal

/configure router bgp group "ibgp-internal" neighbor 10.10.10.1 peer-as 65001

To bring up the BGP one more configuration is required. Need to configure the autonomous system to bring the session up.

/configure router autonomous-system 65001

Let's verify the BGP output:

PE01# show router BGP summary all 
===================================================================
BGP Summary
===================================================================
Neighbor
Description
ServiceId          AS PktRcvd InQ  Up/Down   State|Rcv/Act/Sent (Addr Family) PktSent OutQ
-------------------------------------------------------------------------------------------------------------------
10.10.10.2
Def. Instance   65001       9    0 00h03m22s 0/0/0 (IPv4)  9    0           
-------------------------------------------------------------------------------------------------------------------

By default in Nokia SR, it will form the family IPV4 neighborship if we don't configure any family under the BGP configuration hierarchy.


2. eBGP configuration between PE01 and CE01

External BGP configured between PE01 and CE01 router. CE01 advertise prefixes to PE01 and it propagates it's further to PE02 via pre-configured IBGP session.


PE01:

/configure router bgp group "ebgp-external"

/configure router bgp group "ebgp-external" neighbor 10.1.5.5

/configure router bgp group "ebgp-external" neighbor 10.1.5.5 type external

/configure router bgp group "ebgp-external" neighbor 10.1.5.5 peer-as 65002


CE01:

/configure router bgp group "ebgp-external"

/configure router bgp group "ebgp-external" neighbor 10.1.5.1

/configure router bgp group "ebgp-external" neighbor 10.1.5.1 type external

/configure router bgp group "ebgp-external" neighbor 10.1.5.1 peer-as 65001


CE advertising its system IP to PE01:

CE01# show router BGP summary all 
====================================================================
BGP Summary
====================================================================
Neighbor
Description
ServiceId          AS PktRcvd InQ  Up/Down   State|Rcv/Act/Sent (Addr Family)  PktSent OutQ
------------------------------------------------------------------------------------------------------------------
10.1.5.1
Def. Instance   65001      53    0 00h03m30s 0/0/1 (IPv4) 55    0           
------------------------------------------------------------------------------------------------------------------

Routes received on PE01 router from CE:

PE01# show router bgp routes 
=========================================================================
 BGP Router ID:10.10.10.1       AS:65001       Local AS:65001      
=========================================================================
 Legend -
 Status codes  : u - used, s - suppressed, h - history, d - decayed, * - valid
                 l - leaked, x - stale, > - best, b - backup, p - purge
 Origin codes  : i - IGP, e - EGP, ? - incomplete
=========================================================================
BGP IPv4 Routes
=========================================================================
Flag  Network                                            LocalPref   MED
      Nexthop (Router)                                   Path-Id     Label
      As-Path                                                        
-------------------------------------------------------------------------------
u*>i  10.10.10.5/32                                      None        None
      10.1.5.5                                                   None        -
      65002                                                           
-------------------------------------------------------------------------------
Routes : 1
=========================================================================

PE01 receiving the route from its external BGP and advertises it to PE02 via IBGP.

PE01# show router bgp summary all 
=========================================================================BGP Summary
=========================================================================Neighbor
Description
ServiceId          AS PktRcvd InQ  Up/Down   State|Rcv/Act/Sent (Addr Family) PktSent OutQ
------------------------------------------------------------------------------------------------------------------
10.1.5.5
Def. Instance   65002      35    0 00h03m52s 1/1/1 (IPv4) 60    0           
10.10.10.2
Def. Instance   65001      50    0 00h23m30s 0/0/1 (IPv4) 50    0           
-------------------------------------------------------------------------------------------------------------------

From the above output, we can see 10.1.5.5 is receiving a route via external BGP and advertising it back to its iBGP peer of 10.10.10.2 PE02.

In our, Next Post let's analyze the routes on the PE02 router and how it's installing it in the routing table.


Location: Chennai, Tamil Nadu, India

Comments

Post a Comment

Popular posts from this blog

Image
How to add Cisco IOU Image on Eve-ng Up and Running Step 1# Download Linux L2/L3 adventerprise Image  Step 2# Upload the downloaded image to the EVE path /opt/unetlab/addons/iol/bin/ using WinSCP or Filezilla Step 3# Fix the permission for the added image using the below command /opt/unetlab/wrappers/unl_wrapper -a fixpermissions Step 4# Create an iou keygen file Copy the Cisco IOU Image Script provided below and add to the script vim /opt/unetlab/addons/iol/bin/ioukeygen.py Esc:wq Step 5# Fix the permission for the Python script chmod –x vim /opt/unetlab/addons/iol/bin/ioukeygen.py Step 6# Run the license generator script  /opt/unetlab/addons/iol/bin/ioukeygen.py copy the license generated by the script Step 7# Create iourc license file for your EVE vim /opt/unetlab/addons/iol/bin/iourc Paste the output captured in Step 6 Step 8# Fix the permission and start practicing your lab by adding the image on eve-ng web /opt/unetlab/wrappers/unl_wrapper -a fixpermissions Cisco IOU Image Script
Read more

Configuration of the epipe/l2circuit on the Nokia 7750 SR/7250 IXR

Image
Epipe Configuration on Nokia 7750 SR This article explains how to configure epipe between Nokia SR routers. The Cisco term is referred to as xconnect and the juniper term is L2circuit. Basic Theories: Epipe name itself identifies it's a point-to-point connection that uses Ethernet encapsulation to pass data bits/bytes between two endpoints. Service provider core act as a layer 2 switch for customer traffic. In other words, this helps to extend the IP segment of the same subnet shared between 2 different locations. Topology: ISIS Level 2 and LDP are preconfigured. let's explore the setup to configure epipe and initiate traffic between the 2 sites. LDP is used to signal the Service label between end nodes participating in epipe. Nokia: SAP-MTU and Service MTU play an important role. To bring up the epipe between 2 end nodes we need to take care of Service-MTU and Sap port MTU. SAP-port MTU and Service MTU should be the same if the encapsulation is null. If the encapsulation is do
Read more

How to configure SFM/ Card/MDA in Nokia SR 7750/77XX series routers

Image
We going to discuss how to configure and bring up the Nokia chassis for the first-time installation like SFM, IOM/IMM Card, and MDA on Nokia 7750/77XX series router. SFM Card - Switch Fabric Module which is an internal backplane used to switch traffic between different slots on the router chassis. IMM -    Integrated Media Module which is your line card with a fixed number of media/ports IOM - Input/Output Module this type of card we can insert different types of media/ports based on the supported type by each Chassis. Let us explore how to identify and configure our Nokia SR series routers. 1. First find the SFM Type inserted on the Nokia Router. as per the output we need to configure  SFM5 to bring up the Switch fabric module A:SR1# configure sfm 1 sfm-type m-sfm5-12 Now SFM is configured let's find the Card Type using the "show card" command  *A:SR1# configure card 1 card-type "iom3-xp" Now, we are in the final phase to bring up the ports. check and configur
Read more