Subject: How to find out the port number by IP address
Solution:
In core switch, ping the IP address,
Ex:
telnet@GemHF-Fab-Core#ping 10.20.12.111
Sending 1, 16-byte ICMP Echo to 10.20.12.111, timeout 5000 msec, TTL 64
Type Control-c to abort
Reply from 10.20.12.111 : bytes=16 time=1ms TTL=128
Success rate is 100 percent (1/1), round-trip min/avg/max=1/1/1 ms.
telnet@GemHF-Fab-Core#
And then:
telnet@GemHF-Fab-Core#sh arp 10.20.12.111
IP Address Mac Address Type Age Port Status
1 10.20.12.111 6c62.6d99.023c Dynamic 1 1/19 Valid
telnet@GemHF-Fab-Core#
And we find one device be connected to Port:1/19
But the device‘s IP address is 10.20.12.111?
Let show MAC address again.
telnet@GemHF-Fab-Core#sh mac ethernet 1/19
Total active entries from port 19 = 10
MAC-Address Port Type Index VLAN
0012.f20c.d234 1/19 Dynamic 15838 2
001b.78a5.1abb 1/19 Dynamic 1186 11
6c62.6d99.023c 1/19 Dynamic 9116 12
0022.641b.a7d6 1/19 Dynamic 14968 11
0022.641b.a89f 1/19 Dynamic 7876 11
1cc1.de13.3269 1/19 Dynamic 14167 11
0015.5d0c.6f0b 1/19 Dynamic 10006 12
4061.86c6.9d40 1/19 Dynamic 567 11
9cb6.543a.d6b6 1/19 Dynamic 9426 11
000d.f411.af84 1/19 Dynamic 5002 12
telnet@GemHF-Fab-Core#
We can find not only 6c62.6d99.023cdevice communication by this switch port. So we know a switch or router be connected to this switch port number.
Let me show fdp(Cisco named CDP) neighbor.
telnet@GemHF-Fab-Core#sh fdp neighbors ethernet 1/19
Device ID: HF-OA-B1-1C
configured as tag-type8100
Entry address(es):
IP address: 10.20.0.20
Platform: FES4802 Switch, Capabilities: Switch
Interface: ethernet1/19
Port ID (outgoing port): ethernet50 is TAGGED in following VLAN(s):
2 11
Holdtime : 122 seconds
Foundry Networks, Inc. FES4802, IronWare Version 03.6.00cTc1 Compiled on Oct 31 2006 at 22:18:23 labeled as FES03600c
One device named HF-OA-B1-1C be connected to this port.
Now let‘s login this switch by telnet.
Let‘s ping the IP address: 10.20.12.111 at first.
telnet@HF-OA-B1-1C#ping 10.20.12.111
Sending 1, 16-byte ICMP Echo to 10.20.12.111, timeout 5000 msec, TTL 64
Type Control-c to abort
Reply from 10.20.12.111 : bytes=16 time<1ms TTL=127
Success rate is 100 percent (1/1), round-trip min/avg/max=0/0/0 ms.
telnet@HF-OA-B1-1C#^C
telnet@HF-OA-B1-1C#
And then let‘s show the mac address:
telnet@HF-OA-B1-1C#sh mac-address
Total active entries from all ports = 31
MAC-Address Port Type VLAN
6c62.6d99.0129 50 Dynamic 12
6c62.6d99.0309 50 Dynamic 12
6c62.6d99.023f 50 Dynamic 12
6c62.6d99.023c 7 Dynamic 12
d067.e531.3ec0 50 Dynamic 12
02e0.52ea.ca0c 50 Dynamic 12
02e0.52c5.ca0b 50 Dynamic 11
02e0.522e.ca02 50 Dynamic 2
9cb6.543a.d6b6 22 Dynamic 11
000d.f411.d7d2 50 Dynamic 12
0012.f21a.da00 50 Dynamic 11
0012.f21a.da12 50 Dynamic 11
000d.f410.c492 50 Dynamic 12
0015.5d0c.6f0b 7 Dynamic 12
000d.f411.c18e 50 Dynamic 12
000d.f411.4920 50 Dynamic 11
0022.641b.a7d6 21 Dynamic 11
0022.641b.a89f 14 Dynamic 11
4061.86c8.12a1 50 Dynamic 11
0012.f21b.2500 50 Dynamic 11
000d.f411.af84 7 Dynamic 12
MAC-Address Port Type VLAN
4061.86c6.9d60 50 Dynamic 12
4061.86c6.9d40 25 Dynamic 11
001b.78a5.1abb 23 Dynamic 11
001c.c41e.a6cf 50 Dynamic 11
1cc1.de13.3269 16 Dynamic 11
0012.f21a.da12 50 Dynamic 12
0012.f21b.2500 50 Dynamic 12
0012.f21a.da12 50 Dynamic 2
0012.f21b.2500 50 Dynamic 2
0012.f21a.da00 50 Dynamic 12
We can find the mac-address 6c62.6d99.023c matching with IP address, and the switch port number is 7. but we find not only the mac address communication by this switch port. Let‘s check it again. We find one a small hub is connected to this switch port. So we can ignore this small HUB and think the device directly connected to this port.
Now we have found the switch port.
本文出自 “庐阳侠们” 博客，请务必保留此出处http://c1813.blog.51cto.com/112125/1558343
how to find out the switch port by IP address
原文地址：http://c1813.blog.51cto.com/112125/1558343
