Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 717)

FIGURE 80 Verifying path continuity— second hop TTL count
The table below shows the packet header information for the request and response packets.
Information specific to the Layer 2 traceroute feature is show in bold.
Packet header details with Layer 2 traceroute — second hop TABLE 103
Traceroute request — first hop
(TTL = 2) Traceroute request — second hop
(TTL = 1) Traceroute reply
Outer L2 DA = B1Outer L2 SA =
A1Outer 802.1q tagOuter etype =
TRILLTRILL destination RBridge ID =
CTRILL source RBridge ID = ATRILL
flags: TTL = 2 Inner L2 DA = MAC
2Inner L2 SA = MAC 1
Inner 802.1q tagInner etype = 0x800
TOAM Opcode = 5 (request)
Outer L2 DA = C1Outer L2 SA =
B1Outer 802.1q tagOuter etype =
TRILLTRILL destination RBridge ID =
CTRILL source RBridge ID = ATRILL
flags: TTL = 1 Inner L2 DA = MAC
2Inner L2 SA = MAC 1
Inner 802.1q tagInner etype = 0x800
TOAM Opcode = 5 (request)
Outer L2 DA = B1->A1Outer L2 SA
= C1->B1Outer 802.1q tagOuter
etype = TRILLTRILL destination
RBridge ID = ATRILL source
RBridge ID = CTRILL flags: TTL =
MAX (63) Inner L2 DA = A1Inner L2
SA = B1
Inner 802.1q tagInner etype =
TRILL OAM
TOAM Opcode = 4 (reply)
Tracing a route with the l2traceroute command
In the following example, the l2traceroute command verifies the path between port 3/0/1 (source MAC
address 0050.5685.0003) and port 2/0/9 (destination MAC address 0024.3878.3720).
1. enter the show mac-address-table command to display all known MAC addresses in the network.
switch# show mac-address-table
VlanId Mac-address Type State Ports
100 0024.3878.e720 Dynamic Active Po 11
100 0050.5685.0001 Dynamic Active Po 1
101 0000.0000.0003 Dynamic Active Po 1
101 0024.3878.e720 Dynamic Active Po 11
101 0050.5685.0003 Dynamic Active Po 1
Total MAC addresses : 5
Tracing a route with the l2traceroute command
Network OS Administrator’s Guide 717
53-1003225-04