Cisco 4900Ms are interesting platforms to work with. They are fantastic as layer 2 devices, but with MLS images, I’ve had some “challenges” in the past that resulted in the need for a ROMMON recovery. One of these issues was the switch deciding to format its flash after a reboot (wonderful!).
The ROMMON recovery procedure is a bit different to the norm (in that you use the management port) so it’s posted below. The TFTP server is 10.10.10.48 as an example. All configuration is done via the console port on a remote terminal server.
rommon 1 >set interface fa1 10.0.0.1 255.255.255.0 rommon 2 >set ip route default 10.0.0.254 rommon 3 >boot tftp://10.10.10.48/cat4500e-entservicesk9-mz.122-54.SG1.bin
The switch then boots up via tftp – this may take quite a while depending on bandwidth and latency. As a reference, booting off that image over a 70ms latency Gig link via tftp took 45 minutes so you will have to be patient unless you have someone local with a laptop that can run a server to load the image from. You’ll see the following (love the Star Wars references on this platform!):
Tftp Session details are .... Filename : /cat4500e-entservicesk9-mz.122-54.SG1.bin IP Address : 10.0.0.1 Loading from TftpServer: 10.10.10.48 Received data packet # 50659 Loaded 25936915 bytes successfully. Rommon reg: 0x00004380 Reset2Reg: 0x00001FFF # Tatooine controller 0x0B46AD69..0x0B4D21F5 original size:0x0012635C## Forerunner controller 0x0B4D21F6..0x0B593DC6 original size:0x001CE7CF ################## diagsk5 version 4.1.6
You now have to get an image on to the switch seeing as the IOS image is only in memory, not on flash. You will also need to make a basic config to save. Use FTP at the very least to copy the image down or you will be waiting forever. As per a previous post, the config register must be changed on this platform or you will have headaches later!
Switch>en Switch#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#ip vrf mgmtVrf Switch(config-vrf)#vtp domain null Switch(config)#vtp mode transparent Setting device to VTP Transparent mode for VLANS. Switch(config)#interface FastEthernet1 Switch(config-if)# ip vrf forwarding mgmtVrf Switch(config-if)# ip address 10.0.0.1 255.255.255.0 Switch(config-if)# speed auto Switch(config-if)# duplex auto Switch(config-if)#ip route vrf mgmtVrf 10.10.10.0 255.255.255.0 10.0.0.254 Switch(config)#ip ftp source Fa1 Switch#copy ftp://user:firstname.lastname@example.org//tftpboot/cat4500e-entservicesk9-mz.122-54.SG1.bin bootflash Destination filename [cat4500e-entservicesk9-mz.122-54.SG1.bin]? !!!!(truncated) [OK - 25936915/4096 bytes] 25936915 bytes copied in 528.374 secs (49088 bytes/sec) Switch#dir Directory of bootflash:/ 19 -rw- 25936915 May 13 2013 09:42:20 +00:00 cat4500e-entservicesk9-mz.122-54.SG1.bin 122007552 bytes total (88629248 bytes free) Switch(config)#boot system flash bootflash:cat4500e-entservicesk9-mz.122-54.SG1.bin Switch(config)#config-register 0x2102 Switch(config)#wr mem Building configuration... Compressed configuration from 2735 bytes to 1154 bytes[OK] Switch#sho bootvar BOOT variable = bootflash:cat4500e-entservicesk9-mz.122-54.SG1.bin,1; CONFIG_FILE variable does not exist BOOTLDR variable does not exist Configuration register is 0x102 (will be 0x2102 at next reload) Switch#reload