An engineer is following the proper upgrade path to upgrade a Cisco AireOS WLC from...

When upgrading a Cisco AireOS WLC from version 7.3 to 8.9, it’s crucial to configure ACLs that allow necessary traffic for Cisco Central Web Authentication (CWA). The correct ACLs to configure are:

B. Permit 0.0.0.0 0.0.0.0 UDP DNS any: This ACL allows DNS queries from any source to any destination, which is essential for resolving domain names during the upgrade process.

E. Permit 0.0.0.0 0.0.0.0 UDP any any: This ACL permits all UDP traffic from any source to any destination, ensuring that services relying on UDP can continue to function during the upgrade.

These ACLs ensure that critical services like DNS resolution are not interrupted during the upgrade process, which could otherwise lead to system instability or failure to access network resources. References := ( CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide )