ManuelYu Cross Topic Traps

Users will not be able to resolve domain names, so HTTP access using domain names will fail even if HTTP is permitted. Trigger phrase: DNS first, then HTTP Memory anchor: No name, no access

If traffic is blocked by ACL, QoS policies will not apply because the traffic never reaches classification. Trigger phrase: ACL before QoS Memory anchor: Blocked traffic has no priority

Users can reach external IPs but cannot resolve domain names, making browsing appear broken. Trigger phrase: IP works, name fails Memory anchor: Can reach, can’t find

OSPF advertises VLAN networks through SVIs, allowing routing between VLANs and external networks. Trigger phrase: SVIs advertise VLANs Memory anchor: Routing knows VLANs

Inter-VLAN communication will still work locally, but external routing and remote connectivity will fail. Trigger phrase: Local works, global fails Memory anchor: Inside ok, outside broken

ACL may allow HTTP to one server but block access to other related resources or services required by the website. Trigger phrase: Partial access issue Memory anchor: Main loads, parts don’t

NAT must be configured correctly to avoid translating VPN traffic, otherwise the tunnel may fail or traffic may not match encryption rules. Trigger phrase: NAT vs VPN conflict Memory anchor: Don’t translate encrypted traffic

Devices will receive IP addresses but cannot communicate outside their subnet. Trigger phrase: Wrong gateway Memory anchor: Got IP, no route

VLANs separate networks, but ACLs enforce restrictions. Without ACLs, communication is still allowed through routing. Trigger phrase: Segmentation needs enforcement Memory anchor: Walls need locks

The centralization of NAT and VPN on EDGE-RTR1 introduces a single point of failure for external services. Trigger phrase: Single point risk Memory anchor: One device, big impact