04-07-2011 07:55 AM - edited 03-04-2019 12:00 PM
I'm trying to install ios into my cisco 2821 which boots in rommon. Apparently the ios is corrupted, I have set the IP_ADDRESS, IP_SUBNET_MASK, DEFAULT_GATEWAY, TFTP_SERVER, TFTP_FILE but anytime I issue the 'tftpdnld' and confirm to continue, the process will time out give this error message
" ...........
ARP: address resolution for 10.203.8.49 timed out.
ARP failed with failure code 1. TFTP transfer aborted.
TFTP: Operation terminated prematurely. "
What may have gone wrong. Please help me out.
04-07-2011 08:49 AM
If you aren't on the same subnet, you will need an ip helper address.
To have the Cisco IOS software forward User Datagram Protocol (UDP) broadcasts, including BOOTP, received on an interface, use the ip helper-address interface configuration command. To disable the forwarding of broadcast packets to specific addresses, use the no form of this command.
ip helper-address address
no ip helper-address address
address | Destination broadcast or host address to be used when forwarding UDP broadcasts. There can be more than one helper address per interface. |
Disabled
Interface configuration
Combined with the ip forward-protocol global configuration command, the ip helper-address command allows you to control which broadcast packets and which protocols are forwarded.
One common application that requires helper addresses is Dynamic Host Configuration Protocol (DHCP), which is defined in RFC 1531. DHCP protocol information is carried inside of BOOTP packets. To enable BOOTP broadcast forwarding for a set of clients, configure a helper address on the router interface closest to the client. The helper address should specify the address of the DHCP server. If you have multiple servers, you can configure one helper address for each server. Because BOOTP packets are forwarded by default, DHCP information can now be forwarded by the router. The DHCP server now receives broadcasts from the DHCP clients.
All of the following conditions must be met in order for a UDP or IP packet to be helpered by the ip helper-address command:
•The MAC address of the received frame must be all-ones broadcast address (ffff.ffff.ffff).
•The IP destination address must be one of the following: all-ones broadcast (255.255.255.255), subnet broadcast for the receiving interface; or major-net broadcast for the receiving interface if the no ip classless command is also configured.
•The IP time-to-live (TTL) value must be at least 2.
•The IP protocol must be UDP (17).
•The UDP destination port must be for TFTP, Domain Name System (DNS), Time, NetBIOS, ND, BOOTP or DHCP packet, or a UDP port specified by the ip forward-protocol udp global configuration command.
Note The ip helper-address command does not work on an X.25 interface on a destination router because the router cannot determine if the packet was intended as a physical broadcast.
The following example defines an address that acts as a helper address:
interface ethernet 1
ip helper-address 121.24.43.2
04-07-2011 09:55 PM
vmiller
You have provided nice and helpful information about the ip helper-address command. But the post from Alfred was pretty clear that his router was booting into rommon. And the ip helper-address does not operate in rommon.
Alfred
The output that you give us includes this:
"ARP: address resolution for 10.203.8.49 timed out."
So it is pretty clear that the router has attempted to ARP which means that it things that the destination address is in the local subnet. So perhaps it would help us to understand what is the issue if you could provide specifics for the values of IP_ADDRESS, IP_SUBNET_MASK, DEFAULT_GATEWAY, and TFTP_SERVER. The easy way to do this is to cut and paste the output of the set command.
Given the error message that ARP resolution timed out there are a couple of possible explanations:
- the router believes that the TFTP server is on the local subnet but it is not.
- the router is ARPing for its gateway but the gateway is not responding - perhaps because the gateway address is not correct.
HTH
Rick
04-08-2011 09:38 AM
Hi Rick,
As requested these are the settings on the router.
IP_ADDRESS: 10.203.8.138
IP_SUBNET_MASK: 255.255.255.0
DEFAULT_GATEWAY: 10.203.8.250
TFTP_SERVER: 10.203.8.49
TFTP_FILE: c2800nm-advipservicesk9-mz.124-24.T.bin
TFTP_VERBOSE: Progress
TFTP_RETRY_COUNT: 18
TFTP_TIMEOUT: 7200
TFTP_CHECKSUM: Yes
TFTP_MACADDR: 00:1e:be:01:44:60
GE_PORT: Gigabit Ethernet 0
GE_SPEED_MODE: Auto
command for disaster recovery only.
rommon 13 > existing data in all partitions on flash: will be lost!
rommon 13 > to continue? y/n: [n]: y
rommon 13 >
rommon 13 > resolution for 10.203.8.49 timed out.
rommon 13 > ith failure code 1. TFTP transfer aborted.
rommon 13 >
rommon 13 > ion terminated prematurely.
Looking forward to getting your help. Thanks
Alf.
04-08-2011 10:02 AM
Alf
Thanks for the additional information. It does help to clarify what is happening. Clearly the router is attempting to arp for the tftp server and the arp is failing. At the risk of asking the obvious here are a couple of questions:
- can you verify that the tftp server is active and that its address is 10.203.8.49?
- can you verify that the tftp server is connected to the router on the router interface Gig0?
HTH
Rick
04-10-2011 04:43 PM
Alfred posted this same issue in the Network Management forum where it got an interesting response today. I suggest that all further discussion of this issue be consolidated in the Network Management forum using this URL:
https://supportforums.cisco.com/thread/2077726?tstart=0
HTH
Rick
04-07-2011 10:38 PM
Hey Alfred,
Any ideas why you want to make multiple posts of this same thread?
Anyway ... in one of the threads you created, I asked why not use a media card reader.
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