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eBGP 19 — AS 64530 to AS 65182
Enterprise Advanced 2 devices 4 checked tasks 100 points Plan lab
Peer AS 64530 (Mysuru customer) with its provider AS 65182 over 203.0.38.0/30. Bring the eBGP session up, originate the customer prefix 198.19.18.0/24, and check you learn the provider's 198.18.18.0/24. You build it in a browser, type real commands at each device, and every task below is
checked against the running configuration — so you find out it is wrong before anybody else does.
Open this lab in the simulator
The simulator runs in your browser with nothing to install. This lab is part of the full simulator: open it free for 7 days with a new account, then with a plan. It needs an account, which keeps your progress.
The scenario
Peer AS 64530 (Mysuru customer) with its provider AS 65182 over 203.0.38.0/30. Bring the eBGP session up, originate the customer prefix 198.19.18.0/24, and check you learn the provider's 198.18.18.0/24.
Your role: a network engineer on the enterprise team. Level: Advanced Done when: all 4 goals show as passed (100 points).
Network status
Devices: 2 routers, cabled as drawn. No Layer 1 or Layer 2 faults: every link is connected and up. Customer-Mysuru starts with addresses (G0/1 203.0.38.1/30, L0 198.19.18.1/24). Provider-Dhanbad starts with addresses (G0/1 203.0.38.2/30, L0 198.18.18.1/24) and BGP 65182 already configured. Known problems
The network worked and now does not: the scenario above says what users report. The cause is a configuration fault, not a cable. Find it with show commands (interfaces, routes, neighbours, running-config) before you change anything; fix only what is wrong. Goals
The eBGP session to 203.0.38.2 is Established (40 pts) The customer originates 198.19.18.0/24 (20 pts) The customer learns 198.18.18.0/24 from the provider (20 pts) The provider learns 198.19.18.0/24 (20 pts) The activity, in order
The eBGP session to 203.0.38.2 is Established Why: BGP does nothing until the TCP session is Established. Active or Idle means a wrong AS number, no route to the peer, or a block. Verify with: show ip bgp summary The customer originates 198.19.18.0/24 Why: This is the task that checks your configuration directly: the line must really be there, not just look right. Verify with: show running-config The customer learns 198.18.18.0/24 from the provider Why: BGP only advertises what you tell it to AND what is in the routing table. Verify with: show ip bgp The provider learns 198.19.18.0/24 Why: If the prefix is not in the routing table, the router drops packets for it, whatever else is configured. Verify with: show ip route Tips
Work in the order given: later goals depend on the earlier ones. After every change, run the verify command before moving on; do not guess. Stuck? Read the verify output first. It names the interface, neighbour or route that is wrong. Common mistake: Wrong remote-as — the session sticks in Active Common mistake: A network statement with a mask that does not match the RIB entry Common mistake: Different neighbour addresses on the two ends Why this matters
BGP is the protocol the internet runs on. Two autonomous systems peer over TCP port 179, and each advertises the prefixes it owns with a network statement that must match a route already in its table.
What you will be able to do
Configure an eBGP neighbour with the right AS numbers
Originate a prefix with network and mask
Read show ip bgp summary
The network
ISR 2911 — 2 devices in all, already cabled.
Gi0/1 203.0.38.1/30 Gi0/1 203.0.38.2/30 Customer-Mysuru Provider-Dhanbad Drawn from this lab: devices, cables, ports and the addresses already set. Device Model Address already set
Customer-Mysuru ISR 2911 configure it Provider-Dhanbad ISR 2911 configure it
Cabling
Customer-Mysuru Gi0/1 ↔ Provider-Dhanbad Gi0/1
What is configured at the start
These are already configured when the lab opens — including, where this is a troubleshooting lab, the fault itself:
Customer-Mysuru interface g0/1
ip address 203.0.38.1 255.255.255.252
no shutdown
exit
interface lo0
ip address 198.19.18.1 255.255.255.0
no shutdown
exit Provider-Dhanbad interface g0/1
ip address 203.0.38.2 255.255.255.252
no shutdown
exit
interface lo0
ip address 198.18.18.1 255.255.255.0
no shutdown
exit
router bgp 65182
bgp router-id 2.2.2.2
neighbor 203.0.38.1 remote-as 64530
network 198.18.18.0 mask 255.255.255.0 Tasks, and how each one is checked
Every task is decided by reading the live network — a neighbour in FULL, a ping that succeeds, a line in the running configuration — not by looking for a keyword you typed. The same command shows you what the lab sees.
# Task Pts How to verify it yourself
1 The eBGP session to 203.0.38.2 is Established 40 On Customer-Mysuru: show ip bgp summary — neighbour 203.0.38.2 is Established. 2 The customer originates 198.19.18.0/24 20 On Customer-Mysuru: show running-config contains the line(s) matching network 198\.19\.18\.0 mask 255\.255\.255\.0. 3 The customer learns 198.18.18.0/24 from the provider 20 On Customer-Mysuru: show ip bgp lists 198.18.18.0/24. 4 The provider learns 198.19.18.0/24 20 On Provider-Dhanbad: show ip route lists 198.19.18.0/24.
Stuck? Ask the coach
Tell the coach what you see or what you tried. It gives you a hint, not the answer, the way a senior engineer would. Included with a free trial or any plan.
Ask the coach
Common mistakes
Wrong remote-as — the session sticks in Active
A network statement with a mask that does not match the RIB entry
Different neighbour addresses on the two ends
Reference solution
Try it yourself first — the lab checks your work either way. This is one configuration that makes every task pass, device by device:
Customer-Mysuru router bgp 64530
bgp router-id 1.1.1.1
neighbor 203.0.38.2 remote-as 65182
network 198.19.18.0 mask 255.255.255.0
exit Where this is examined
CCNP ENARSI BGP; CCIE EI BGP; Network+ 2.1.
This lab practises these topics in the zNetLaB certification courses:
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