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Four vendors, one OSPF area
Enterprise Advanced 6 devices 5 checked tasks 100 points Plan lab
Cisco, Arista, FRRouting and Juniper in a line, and one OSPF area across all of them. Each takes the commands its own CLI takes — an Arista that routes nothing until “ip routing”, FRR behind vtysh with prefix syntax, Junos in set/commit — and every one still becomes a neighbour. The protocol was never the vendor’s. 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
Cisco, Arista, FRRouting and Juniper in a line, and one OSPF area across all of them. Each takes the commands its own CLI takes — an Arista that routes nothing until “ip routing”, FRR behind vtysh with prefix syntax, Junos in set/commit — and every one still becomes a neighbour. The protocol was never the vendor’s.
Your role: a network engineer on the enterprise team. Level: Advanced Done when: all 5 goals show as passed (100 points).
Network status
Devices: 4 routers, 2 PCs, cabled as drawn. No Layer 1 or Layer 2 faults: every link is connected and up. R-Cisco starts with addresses (G0/0 10.1.0.1/24, G0/1 10.0.12.1/30). H1 is a host with 10.1.0.10/24, gateway 10.1.0.1. H2 is a host with 10.4.0.10/24, gateway 10.4.0.1. R-Arista, R-FRR, R-Juniper start with an empty configuration. 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 Cisco and the Arista are neighbours (20 pts) FRRouting is a neighbour of both of its neighbours (20 pts) And so is the Juniper, in its own language (20 pts) The Cisco learns the Juniper’s LAN end to end (20 pts) A host at one end of the chain reaches the other (20 pts) The activity, in order
The Cisco and the Arista are neighbours Why: OSPF routes only flow over a FULL adjacency. If a neighbour is stuck in INIT or EXSTART, compare the two ends’ settings. Verify with: show ip ospf neighbor FRRouting is a neighbour of both of its neighbours Why: OSPF routes only flow over a FULL adjacency. If a neighbour is stuck in INIT or EXSTART, compare the two ends’ settings. Verify with: show ip ospf neighbor And so is the Juniper, in its own language Why: OSPF routes only flow over a FULL adjacency. If a neighbour is stuck in INIT or EXSTART, compare the two ends’ settings. Verify with: show ip ospf neighbor The Cisco learns the Juniper’s LAN end to end 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 A host at one end of the chain reaches the other Why: A ping needs a route in BOTH directions. This is the end-to-end proof that everything before it worked. Verify with: ping 10.4.0.10 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. Why this matters
Cisco, Arista, FRRouting and Juniper in a line, and one OSPF area across all of them. Each takes the commands its own CLI takes — an Arista that routes nothing until “ip routing”, FRR behind vtysh with prefix syntax, Junos in set/commit — and every one still becomes a neighbour. The protocol was never the vendor’s.
What you will be able to do
The Cisco and the Arista are neighbours
FRRouting is a neighbour of both of its neighbours
And so is the Juniper, in its own language
The Cisco learns the Juniper’s LAN end to end
The network
ISR 2921, Arista vEOS Router, FRRouting, vMX, PC — 6 devices in all, already cabled.
Gi0/1 10.0.12.1/30 Eth1 Eth2 eth0 eth1 ge-0/0/0 Gi0/0 10.1.0.1/24 Fa0 ge-0/0/1 Fa0 R-Cisco R-Arista R-FRR R-Juniper H1 10.1.0.10/24 · gw 10.1.0.1 H2 10.4.0.10/24 · gw 10.4.0.1 Drawn from this lab: devices, cables, ports and the addresses already set. Device Model Address already set
R-Cisco ISR 2921 configure it R-Arista Arista vEOS Router configure it R-FRR FRRouting configure it R-Juniper vMX configure it H1 PC 10.1.0.10 / 255.255.255.0 gw 10.1.0.1 H2 PC 10.4.0.10 / 255.255.255.0 gw 10.4.0.1
Cabling
R-Cisco Gi0/1 ↔ R-Arista Ethernet1 R-Arista Ethernet2 ↔ R-FRR eth0 R-FRR eth1 ↔ R-Juniper ge-0/0/0 R-Cisco Gi0/0 ↔ H1 Fa0 R-Juniper ge-0/0/1 ↔ H2 Fa0
What is configured at the start
These are already configured when the lab opens — including, where this is a troubleshooting lab, the fault itself:
R-Cisco interface GigabitEthernet0/0
ip address 10.1.0.1 255.255.255.0
no shutdown
exit
interface GigabitEthernet0/1
ip address 10.0.12.1 255.255.255.252
no shutdown
exit R-Arista interface Ethernet1
no switchport
ip address 10.0.12.2/30
exit
interface Ethernet2
no switchport
ip address 10.0.23.1/30
exit R-FRR vtysh
interface eth0
ip address 10.0.23.2/30
exit
interface eth1
ip address 10.0.34.1/30
exit
exit R-Juniper configure
set interfaces ge-0/0/0 unit 0 family inet address 10.0.34.2/30
set interfaces ge-0/0/1 unit 0 family inet address 10.4.0.1/24
commit
exit 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 Cisco and the Arista are neighbours 20 On R-Cisco: show ip ospf neighbor shows at least 1 neighbour(s) in FULL. and On R-Arista: show ip ospf neighbor shows at least 2 neighbour(s) in FULL. 2 FRRouting is a neighbour of both of its neighbours 20 On R-FRR: show ip ospf neighbor shows at least 2 neighbour(s) in FULL. 3 And so is the Juniper, in its own language 20 On R-Juniper: show ip ospf neighbor shows at least 1 neighbour(s) in FULL. 4 The Cisco learns the Juniper’s LAN end to end 20 On R-Cisco: show ip route lists 10.4.0.0/24. 5 A host at one end of the chain reaches the other 20 On H1: ping 10.4.0.10 must succeed.
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
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:
R-Cisco router ospf 1
router-id 1.1.1.1
network 10.0.12.0 0.0.0.3 area 0
network 10.1.0.0 0.0.0.255 area 0 R-Arista ip routing
router ospf 1
router-id 2.2.2.2
network 10.0.12.0/30 area 0.0.0.0
network 10.0.23.0/30 area 0.0.0.0 R-FRR vtysh
router ospf
ospf router-id 3.3.3.3
network 10.0.23.0/30 area 0
network 10.0.34.0/30 area 0
exit R-Juniper configure
set routing-options router-id 4.4.4.4
set protocols ospf area 0.0.0.0 interface ge-0/0/0
set protocols ospf area 0.0.0.0 interface ge-0/0/1
commit
exit Where this is examined
This lab practises these topics in the zNetLaB certification courses:
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