Interfaces FE on Cisco 2821 problem

You could assign each of the 8 FE ports to a differnet VLAN thereby allowing you to use up to 8 differnet IP addresses.

Where are you trying to ping the IP address 1`92.168.0.1 from ?

- within the router (ie from the console port or from a router telnet session) or from an external device?

Try pinging from console first, then telnet, then external

To ping from the console connect a PC to the console port usually a blue cable provided by Cisco.

Enter the command "ping 192.168.0.1" at the router prompt

Disable any firewall software running on the PC.

Telnet to router and ping 192.168.0.2 and then dispaly the ARP cache by uisng the command show ip arp 192.168.0.2

On the PC go to an command window, ping the IP address 192.168.0.1 and then issue command arp -a and see if you see the MAC address for the router port.

Post the output of sh int fa 0/3/8 sh int vlan 192

So what you have learned is that ping (ICMP) is failing because neither the PC nor the router get an ARP reply from each other.

To confirm, enable logging buffer and then the following debugs

conf t logging buffer exit wri mem

debug ip icmp debug arp

then try to ping 192.168.0.2

Load Etherreal onto the PC and see if it is receiving any ARP requests from the router.

Also make sure that the PC's NIC and the switch port have the same duplex and speed settings ( ie both auto or both with same fixed value for duplex and speed).

sorry, to see the debug output enter the command "show log"

sorry, to see the router debug output enter the command "show log" BTW the other way of doing this is to configure logging monitor debugging and then enter the command terminal monitor, then you will see the debug output in real time

I do not know linux so I cannot comment on the eth0 versus eth1.

Do you have a Windows PC that you can connect to the router port ?

What the last test showed you is that you Linux PC is receiving an ARP request form the router, perhaps the Linux PC is sending the ARP reply to the wrong logical/physical interface ??? Does the Linux box have multiple NICs in it ?

ie did you config the IP address 192.168.0.2 on thelinux box interface that is connected to the Cisco router ???

Hello,

I have a Cisco 2821 router. It has 2 GigabitEthernet interfaces and 8 FastEthernet interfaces. But FE interfaces don't allow for assigning them IP addresses ("IP addresses may not be configured on L2 links."). Is there any possibility to do this? Other words - I want them to behave the same as GE.

And the second thing. Trying to walkaround this, I made a VLAN, assigned it an IP address and make one of FE interefaces a member of it. I was hoping that, when I ping that address, the answer will be from the assigned interface. But it wasn't happen (there was no ping reply). Is this correct behaviour? And if yes, what is the reason for assigning an IP address for VLAN?

So I can't have more than two interfaces with IP addresses?

But the interface is up. It is like that:

... FastEthernet0/3/8 unassigned YES unset up up ... Vlan192 192.168.0.1 YES TFTP up up

And the configuration: interface FastEthernet0/3/8 switchport access vlan 192 no ip address ! interface Vlan192 ip address 192.168.0.1 255.255.255.0 ip nat inside !

And connecting PC to one of that port it will be allow to ping that interface?

I have a PC connected to the FE 0/3/8 interface and I'm using ping on it.

I don't understand how to ping from the console.

I can ping it when I telnet to the router:

xxx#ping 192.168.0.1

Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

But when I connect a PC with 192.168.0.2 address to the FE 0/3/8 port, it can't ping 192.168.0.1.

There isn't any firewall.

Protocol Address Age (min) Hardware Addr Type Interface Internet 192.168.0.2 0 Incomplete ARPA

So the ARP couldn't determine the MAC address of 192.168.0.2?

The same: ? (192.168.0.1) at on eth1

FastEthernet0/3/8 is up, line protocol is up Hardware is Fast Ethernet, address is 0013.808a.8be8 (bia 0013.808a.8be8) MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s ARP type: ARPA, ARP Timeout 04:00:00 Last input 03:38:00, output never, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 5571 packets input, 522914 bytes, 0 no buffer Received 5043 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 12233 packets output, 945178 bytes, 0 underruns 0 output errors, 0 collisions, 3 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out

Vlan192 is up, line protocol is up Hardware is EtherSVI, address is 0012.80b6.5538 (bia 0012.80b6.5538) Internet address is 192.168.0.1/24 MTU 1500 bytes, BW 100000 Kbit, DLY 1000000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:08, output never, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 5458 packets input, 491443 bytes, 0 no buffer Received 5458 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 5474 packets output, 418931 bytes, 0 underruns 0 output errors, 1 interface resets 0 output buffer failures, 0 output buffers swapped out

Yes, now I know that.

Done.

Nothing happens. No debug output is displayed. I also tried to ping router from PC.

I have linux on that machine with no GUI. But I started a tcpdump (tcpdump arp) and get this output:

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes

17:10:02.502660 arp who-has 192.168.0.2 tell rtr-ipbx01.f1.pl 17:10:02.504015 arp reply 192.168.0.2 is-at 00:11:43:d9:83:7b

But the ifconfig looks like this: ... eth1 Link encap:Ethernet HWaddr 00:11:43:D9:83:7C inet addr:192.168.0.2 Bcast:192.168.0.255 Mask:255.255.255.0

Why eth0 gets the ARP requests? eth1 has no ARP entries in tcpdump.

You probably have the cables in the wrong port on your Linux box or do you have the same IP address on both eth0 & eth1? The above arp suggests that eth0 (00:11:43:d9:83:7b) is responding to 192.168.0.2 but the ifconfig says eth1 also has the same IP. Looks like your doing something strange.

Is you Linux box doing any bridging or routing ??

It looks like too me your traffic on eth1 trying to use eth0 to get to the router.

Thats just a guess ... would need more info. ie

Linux Box run and display output

netstat -r

ifconfig -a

Neil Cherry napisa³(a):

Yes, exactly. I was connecting cable to the one computer, but configuring the other. Shame on me and my boss (who gave me that computer as the correct one)... I realized this after using mii-tool.

Sure. You put the ports in "routed mode". Example: int fa0/0 no switchport ip address 10.1.1.1 255.255.255.0 etc. . . .