Medianet Reference Guide - Cisco

Cisco Network Analysis Module
Chapter 6
Medianet Management and Visibility Design Considerations
However, simply because an interface is determined to be experiencing drops does not necessarily mean
that the interface is relevant to the path of the video flow in question. You may still need to run the show
ip cef exact-route command, or consult the IP routing tables via the show ip route command to
determine whether the particular interface experiencing drops is along the path of the video flow.
Example 6-14 shows an example output from both of these commands.
Example 6-14
Example Output from the show ip route and show ip cef exact-route Commands
me-westdist-3#show ip route 10.17.1.0
Routing entry for 10.17.1.0/24
Known via "eigrp 111", distance 90, metric 6144, type internal
Redistributing via eigrp 111
Last update from 10.17.100.29 on GigabitEthernet1/1, 2w2d ago
Routing Descriptor Blocks:
* 10.17.100.17, from 10.17.100.17, 2w2d ago, via GigabitEthernet5/3
Route metric is 6144, traffic share count is 1
Total delay is 140 microseconds, minimum bandwidth is 1000000 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 4
10.17.100.29, from 10.17.100.29, 2w2d ago, via GigabitEthernet1/1
Route metric is 6144, traffic share count is 1
Total delay is 140 microseconds, minimum bandwidth is 1000000 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 4
me-westdist-3#show ip cef exact-route 10.24.1.11 10.17.1.20
10.24.1.11 -> 10.17.1.20 : GigabitEthernet1/1 (next hop 10.17.100.29)
Example 6-14 shows that the IP routing tables indicate that there are equal-cost paths to IP subnet
10.17.1.20 through next hops 10.17.100.17 and 10.17.100.29, via interfaces GigabitEthernet5/3 and
GigabitEthernet1/1, respectively. The asterisk next to the 10.17.100.17 route indicates that the next
session will follow that route. However, the output from the show ip cef exact-route command shows
that the Cisco Express Forwarding table has already been populated with a session from source IP
address 10.24.1.11, corresponding to the CTS-1000, to destination IP address 10.17.1.20, corresponding
to the Cisco TelePresence Multipoint Switch, via interface GigabitEthernet1/1. Therefore, when
troubleshooting drops along the path for this particular video flow, you should be concerned with drops
shown on interface GigabitEthernet1/1.
Having determined which relevant interfaces are currently experiencing drops, you can drill down
further into the interface via the show interface command. Example 6-15 shows an example
output from this command on a Cisco Catalyst 6500 platform.
Example 6-15
Example Output from the show interface Command
me-westdist-3#show interface gigabitethernet1/1
GigabitEthernet1/1 is up, line protocol is up (connected)
Hardware is C6k 1000Mb 802.3, address is 0018.74e2.7dc0 (bia 0018.74e2.7dc0)
Description: CONNECTION TO ME-WESTCORE-2 GIG1/25
Internet address is 10.17.100.30/30
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s
input flow-control is off, output flow-control is off
Clock mode is auto
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:04, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:13:53
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0! Input & output
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Medianet Reference Guide
OL-22201-01