new to hashcat trying to learn
hi everyone, i 'm reading around and not finding any help.i have this situation:
hashcat -a 3 -m 2500  prova.hccapx  -1 ?l?d  ?1?1?1?1?1?1?1?1 .
i know my password is  lower alpha numeric 8 char long. 
i  also know that the 2 and 4 char are equal .  so now how i can set  hashcat to use the same letter or number at  position 2 and 4 ? i know i can do it manualy but that way i need start hashcat 36 time.
One possible solution would be to create a Maskfile

hashcat -a 3 -m 2500 Prova.hccapx -1 ?l?d masks.hcmask

cat masks.hcmask
please remember that the custom charsets must be set within the hashcat mask file:

hashcat -m 2500 -a 3 -w 3 Prova.hccapx masks.hcmask

the masks.hcmask file is this one:
thanks guys, working good!