Packet Captures
UDLD.cap 3.3 KB
Submitted Sep 14, 2009
Unidirectional Link Detection (UDLD) is used to monitor the status of a link between a Catalyst 2960 and a Catalyst 3560. Note that echos are initially sent at very small intervals, gradually throttling back to the configured interval of 15 seconds.
| Packets: 29 | Duration: 93s | Downloads: 10271 |
TDP.cap 2.8 KB
Submitted Sep 14, 2009
P2 and PE2 exchange Tag Distribution Protocol hellos and form an adjacency over TCP port 711.
| Packets: 33 | Duration: 47s | Downloads: 6408 |
HSRP_failover.cap 3.0 KB
Submitted Sep 14, 2009
R1 is the active router, R3 is the standby, and R2 is passive. R1 goes offline and R3 takes over as active after ten seconds. R2 is then promoted to the standby state.
| Packets: 39 | Duration: 47s | Downloads: 7592 |
HSRP_election.cap 3.7 KB
Submitted Sep 14, 2009
The Ethernet link shared by routers 1, 2, and 3 comes online. R1 wins the HSRP election because it has a priority of 200 (versus the default of 100 held by the other two routers). R3 becomes the standby router.
| Packets: 49 | Duration: 57s | Downloads: 7038 |
HSRP_coup.cap 3.9 KB
Submitted Sep 14, 2009
Initially only routers 3 (active) and 2 (standby) are online. R1 comes online with a priority higher than R3's. R1 takes over as the active router (the coup occurs in packet #22) almost immediately. R2 is bumped down to passive and R3 becomes the standby router.
| Packets: 51 | Duration: 49s | Downloads: 6245 |
HDLC.cap 3.4 KB
Submitted Sep 14, 2009
ICMP across an HDLC serial link.
| Packets: 38 | Duration: 111s | Downloads: 6916 |
EIGRP_subnet_up.cap 1.3 KB
Submitted Sep 14, 2009
R4's 192.168.4.0/24 subnet is brought online. R1 receives updates from both R2 and R3 (only R2's update is shown in the capture). The poison-reverse in packet #9 informs R2 not to use R1 as a path to 192.168.4.0/24. The capture perspective is from R1's 10.0.0.1 interface.
| Packets: 15 | Duration: 18s | Downloads: 8055 |
EIGRP_subnet_down.cap 1.8 KB
Submitted Sep 14, 2009
R4's interface to 192.168.4.0/24 goes down and the route is advertised as unreachable. Queries are issued by all routers to find a new path to the subnet but none exists, and the route is removed from the topology. Capture perspective is from R1's 10.0.0.1 interface.
| Packets: 21 | Duration: 23s | Downloads: 6065 |
EIGRP_goodbye.cap 1.3 KB
Submitted Sep 14, 2009
R2 designates its interface facing R1 as passive. The final hello message from R2 (packet #9) has all its K values set to 255, designating the message as a "goodbye." Capture perspective is from R1's 10.0.0.1 interface.
| Packets: 15 | Duration: 43s | Downloads: 7669 |
EIGRP_adjacency.cap 5.1 KB
Submitted Sep 14, 2009
Formation of an EIGRP adjacency between routers R1 and R2. Capture point is R1's 10.0.0.1 interface.
| Packets: 53 | Duration: 104s | Downloads: 10287 |
EIGRPv2_subnet_transition.cap 5.3 KB
Submitted Sep 14, 2009
R4's 2001:db8:0:400::/64 subnet goes down, then comes back up roughly thirty seconds later. Capture perspective from R1's 2001:db8:0:12::1 interface.
| Packets: 49 | Duration: 65s | Downloads: 6243 |
EIGRPv2_adjacency.cap 4.1 KB
Submitted Sep 14, 2009
Routers 1 and 2 form an EIGRPv2 adjacency and exchange IPv6 routes.
| Packets: 31 | Duration: 52s | Downloads: 8046 |
DTP.cap 934 bytes
Submitted Sep 14, 2009
Dynamic Trunking Protocol (DTP) emanated from a Catalyst 3560 every 60 seconds, both with and without ISL encapsulation.
| Packets: 10 | Duration: 120s | Downloads: 8692 |
3725_CDP.cap 390 bytes
Submitted Sep 14, 2009
Cisco Discovery Protocol (CDP) from FastEthernet0/0 of a Cisco 3725 router.
| Packets: 1 | Duration: n/a | Downloads: 6443 |