Regex to Match Private AS Numbers
Posted on May 16 2023 under networking and regex
16-bit Private ASNs (64512 to 65534)
6451[2-9]|645[2-9][0-9]|64[6-9][0-9]{2}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-4]
32-bit Private ASNs (4200000000 to 4294967294)
42[0-8][0-9]{7}|429[0-3][0-9]{6}|4294[0-8][0-9]{5}|42949[0-5][0-9]{4}|429496[0-6][0-9]{3}|4294967[01][0-9]{2}|42949672[0-8][0-9]|429496729[0-4]
Combined
6451[2-9]|645[2-9][0-9]|64[6-9][0-9]{2}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-4]|42[0-8][0-9]{7}|429[0-3][0-9]{6}|4294[0-8][0-9]{5}|42949[0-5][0-9]{4}|429496[0-6][0-9]{3}|4294967[01][0-9]{2}|42949672[0-8][0-9]|429496729[0-4]