Help needed...........trying to configure Ethernet port on a 1841 router (Bad Mask)

Engineer66

Hi all,

I need a little help please? I'm trying to configure the ethernet ports on two 1841 routers that I have just recently purchased for my LAB, but hitting the same issues all the time, getting "Bad mask 0E1E1E100" on both of the routers. I have carried out factory re-set, but still have no joy on any subnet configuration I enter. I can get one of the ethernet ports up as management access, using the configuration wizard durning initial boot up (but dont want that do we). Don't know where I'm going wrong, Its driving me crazy.....................

R1>en
R1#config t
Enter configuration commands, one per line. End with CNTL/Z.
R1 (config)# interface fastethernet 0/0
R1 (config-if)#ip add 192.168.1.4 225.225.225.0
Bad mask 0xE1E1E100 for address 192.168.1.4
R1 (config-if)

jdballinger

Your mask is wrong for sure. Do you mean to put 255 instead of 225?

TechGuru80

255 not 225...bad mask all day.

Engineer66

Sorry guys, bad typo error, its is ment to be 255 and not 225! typo when posting in on here

Engineer66

Any Idea's, get the same bad mask 0xE1E1E100, if I try to configure a serial card on the router, any help would be greatly appreciated.

BobBobson

You have the wrong subnet mask configured for the address you are trying to assign, the "Bad mask 0xE1E1E100" is telling you the subnet mask you are trying to configure in hexadecimal, it translates into decimal as "bad mask 225.225.225.0". Try using the subnet mask "255.255.255.0" instead.

Engineer66

As I said that was a typo when I was writing it up on here! I'm using had have been using 255.225.255.0

BobBobson

"255.225.255.0" The bolded part is your issue in that case, the first 3 octets should be "255".

Engineer66

Sorry mate I'm at my wits end I keep on doing bad typos on here, I have been using 255.255.255.0 all along. its driving me crazy

BobBobson

No problems

I would still double check that you were DEFINITELY configuring 255.255.255.0 as your subnet mask, because if you directly copy and pasted that error "Bad mask 0xE1E1E100" is indicating that you did not. Try typing "ip add 192.168.1.4 255.255.255.0".

Engineer66

cheers Bob, tried it again still the same double checking lol!

R1>en
R1#config t
Enter configuration commands, one per line. End with CNTL/Z.
R1 (config)# interface fastethernet 0/0
R1 (config-if)#ip add 192.168.1.4 255.255.255.0
Bad mask 0xE1E1E100 for address 192.168.1.4

I have even tried subnet-zero command, but still no joy!

BobBobson

That is quite odd :S

Try clearing the IP address with "no ip add" then try entering it again, if that doesn't work than maybe try different network for your address (I.E. "ip add 192.168.20.4 255.255.255.0") and see if THAT works.

clarson

I'd try the same thing as bob suggested. being you type in 255.255.255.0 and the ios give you an error saying 225.225.225.0 is a bad mask. which it is because subnet mask start with a series of ones and ends with a series of zeros. there can't be any mixing of ones and zeros. So, lets see what does work. start with the no ip address. Then start assigning an address using the subnet mast of 128.0.0.0, then 192.0.0.0, then 224.0.0.0, then 240.0.0.0, etc

TechGuru80

What does your startup config look like?

Engineer66

Hi Guys,

managed to get it sorted by entering the command
"(config)#default interface fa0/0" to reset the port then the command "ip add 192.168.1.4?" the reply back I got was A.B.C.D then I was able to configure the port correctly with the mask of 255.255.255.0. I dont know why it was not letting be do it before with the correct mask, but all sorted now.

I big thanks to all who helped

theodoxa

Here's the odd part, 0xE1E1E100 = 225.225.225.0

255.255.255.0 = 0xFFFFFF00