> # About the DHCHAP Hash Algorithm

> Cisco MDS switches support a default hash algorithm priority list of MD5 followed by SHA-1 for DHCHAP authentication.

> Tip If you change the hash algorithm configuration, then change it globally for all switches in the fabric.

> Caution | RADIUS and TACACS+ protocols always use MD5 for CHAP authentication. Using SHA-1 as the hash algorithm may prevent RADIUS and TACACS+ usage—even if these AAA protocols are enabled for DHCHAP authentication.

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