I was configuring a routed port on a 3560 when I ran across an interesting error:
sw1(config-if)#ip add 126.96.36.199 255.225.255.0
Bad mask 0xFFE1FF00 for address 188.8.131.52
I LOVE it when my switch speaks hex to me. HOT!!!
I’m not sure why it pointed out my fat-fingered mistake via hex rather than decimal, but it’s pretty easy to decode this one. My mask should have been 255.255.255.0 or FFFFFF00 in hex.