rommon recovery of 3750-x switch

3750-x switch is having an advanced feature for rommon recovery. for other switches we used to do xmodem recovery. for 3750-x switch we do not have to waste time like that.

follow the procedure, we can set the ipaddress even in the rommon prompt and transfer the image

Step 1 Connect your PC to the switch Ethernet management port.

Step 2 Unplug the switch power cord.

Step 3 Press the Mode button, and at the same time, reconnect the power cord to the switch.

You can release the Mode button a second or two after the LED above port 1 goes off. Several lines of information about the software appear with instructions:

The system has been interrupted prior to initializing the flash file system. The following
commands will initialize the flash file system, and finish loading the operating system



Step 4 Initialize the flash file system:

switch: flash_init

Step 5 Connect the switch to a TFTP server through the Ethernet management port.

Step 6 Start the file transfer by using TFTP.

a. Specify the IP address of the TFTP server:

switch: set ip_addr ip_address/mask

b. Specify the default router:

switch: set default_router ip_address

Step 7 Copy the software image from the TFTP server to the switch:

switch: copy tftp://ip_address/filesystem:/source-file-url flash:image_filename.bin

Step 8 Boot up the newly downloaded Cisco IOS image.

switch: boot flash:image_filename.bin

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transceiver modules compatibility matrix Cisco

The possible ways to connect the transceiver modules.





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Etherswitch modules configuration questions

1) what is the difference between HWIC-4ESW and Etherswitch modules.

HWIC-4ESM cards are high speed wan interface cards.  its basically a layer 2 switch with provisions for POE. ES modules are like switches inside a router slot, THE ES modules are insallted in the NM slots. We can acccess these ES modules and we can do ios upgrade also separately. This is not possible with the HWIC cards.

When we have HWIC cards installed in the router, the ports will be shown in the sh ip int brief as fastethernet ports in the router.

But when we have ES modules, the port which is  internally connecting to ES  module will be shown in the show ip int brief . like gig 4/0 or gig 2/0 depending  on the slot its installed. We have to configure a ip address for the gig port and log into the ES module using the command

“service-module gig 4/0 session ”

Once we are in the service module   either you can configure an ip address to the internal port connecting from the switch to the router, or we can configure the ip address for the vlan. by default the port connecting to the router is in the vlan 1 .

then for the internal communication we should have the ip route statement on both the ES and the router .
show inv:
NAME: “NME-XD-48ES-2S-P: EtherSwitch SM 48 10/100T PoE + 2 SFP on Slot 4”, DESCR: “NME-XD-48ES-2S-P: EtherSwitch SM 48 10/100T PoE + 2 SFP”

router#sh ip int brief
Interface                  IP-Address      OK? Method Status                Protocol

GigabitEthernet4/0        YES manual up                    up

router#service-module gigabitEthernet 4/0 session

this will log you into the service module.

ESW-module#GigabitEthernet1/0/4   unassigned      YES unset  up                    up

gig 1/0/4 port is the interface connect to the router via the backplance

either we can give an ip address to this gig1/0/4 or put an ip address to the vlan 1 . by default this port is in vlan 1
ESW-module(config)#interface  vlan  1

ESW-module(config-if)#ip address

ESW-module(config)#ip route is the gig 4/0 ip address on the router through which the packets go out the router.

create anotther vlan for the internal communication for the hosts
ESW-module(config)#interface  vlan  20

ESW-module(config-if)#ip address

also create a route in the router for reaching the vlan 20 in the ES module. this is reachable via which is the vlan 1 ip address in the switch


router(config)#ip route

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3750-x switch with lanbase feature unable to stack with other 3750G/3750E switches

Issue:  Cisco 3750-X switch with lan base feature set unable to stack with other 3750G/3750E switch

Solution: the 3750-X switch with lan base feature set  will only stack with another 3750-x switch running lan base.

Workaround: install the license set ipbase or ipservices in the 3750-X.  you may have to purchase the license. 3750-x switch with ipbase or ipservices whould be able to stack with the other switches. mix of 3750-x,3750G,3750E switches are  supported in the stack.

Also, 3750-X switch with universal image comes with ipservices as an evaluation license. you can use the evaluation license as a temporary workaround .

you can verify this using “show license detail”.  If the ipservices is listed as an evaluation license you can use the below command to activate it and stack with the other switches. The evaluation license time period is 8 weeks, before that you need to purchase it.

command reference:  to set the switch to boot the license

Switch#conf t
switch(config)# licence boot level ?



Switch# reboot

< after you install the license you need to reboot the switch . before rebooting please verify the license is activated by using the command “show version”. there you will see that the current license is lanbase and next reboot it will be “ipservices”. if this is not listed like that then the evaluation license is not being activated.






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My first blog entry

I have been in the networking industry for quite a long time. today I thought of preparing some documents in design, troubleshooting and knowledge sharing in networking. I find this space will be better place to share my knowledge.

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Hello world!

Welcome to This is your first post. Edit or delete it and start blogging!

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