why i have invalid marker on mac address when it has "x"

[dolas2005]

Hi I'm new to Cisco Packet Tracer and I've been doing some stuff with mac addresses and when i tried changing it for aaaa.2x22.cccc it showed as invalid but when i used aaaa.2a22.cccc it did. Any Ideas I'm just intrested?

[Ruben Cocheno · Accepted solution]

@dolas2005 

MAC addresses are 12-digit (6 bytes or 48 bits) hexadecimal, it uses sixteen distinct symbols, most often the symbols "0"–"9" to represent values 0 to 9, and "A"–"F.

Because you using x (not part of hexadecimal) it throws you an error

[dolas2005]

Thx it now makes sense and I totally forgot fact about MAC address being hexadecimal.

[M02@rt37 · Accepted solution]

Hello @dolas2005 

The MAC address you use must follow specific rules. The letters in a MAC address are hexadecimal, meaning they can only be 0-9 or A-F (or a-f, as it's case-insensitive). In your example, "aaaa.2x22.cccc" is invalid because 'x' is not a valid hexadecimal digit, while "aaaa.2a22.cccc" is valid as 'a' is a valid hexadecimal digit.

So, when working with MAC addresses in Cisco Packet Tracer or any networking environment, ensure that you only use valid hexadecimal digits (0-9, A-F or a-f) to avoid any errors or inconsistencies.