Troubleshooting Network Configurations: OSPF, RADIUS, ACLs

Posted on Mar 3, 2025 in Computers

Network Configuration Issues and Solutions

This document addresses various network configuration issues and provides solutions. The topics covered include OSPF, RADIUS, Access Control Lists (ACLs), Virtual Switching Framework (VSF), and more.

OSPF Configuration

  • Configure Area 1 as a stub area, with no summaries on Switch-2.
  • Set a cost of 100 in the redistribute static command on Switch-1 to change the external LSA metric.
  • Enable BFD in asynchronous mode on each OSPF routing switch in VLAN 100.
  • Use virtual link 2 OSPF to create a connection between two areas that are not directly connected to Area 0.
  • The ABRs create a discontinuous area and disrupt intra-area routing between devices within Area 1. Endpoints within Area 1 will no longer be able to reach endpoints in other areas.
  • Configure 10.0.0.1 on a loopback interface, and enable OSPF on that interface.
  • Change Area 3 to Area 0, remove Area 1 from Switch-2 and Area 2 from Switch-1.
  • Set the update source for the neighbor to the local loopback interface on each switch.
  • Hello packets permit an OSPF adjacency between two VSF fabrics.
  • In the Switch-1 OSPF Area 0 configuration.

RADIUS and MAC Authentication

  • RADIUS MAC Authentication should be enabled on the guest ports.
  • Set an 802.1X client limit of 2 on interface 1.
  • Enable dynamic authorization in the RADIUS server settings.
  • Authenticated devices must receive their dynamic settings, such as VLAN ID and ACLs, from the RADIUS server Access-Accept.
  • To enhance the security of an 802.1X solution.
  • Permit “Allow All MAC-Auth” on the ClearPass Portal.
  • Set 802.1X client limit on the interfaces.
  • It authenticates control traffic between the switch and its Mobility Controller.

Access Control Lists (ACLs)

  • Enable ACL grouping, and apply ACLs as shared ACLs.
  • Resequence the ACL with more space, then add the new rule with a sequence ID before the ID for the current third rule.
  • Traffic must be permitted by both the dynamic ACL and the VLAN ACL in order to be permitted.
  • Ethertype and Class of Service: an extended MAC ACL only.

Virtual Switching Framework (VSF)

  • The proposed switches should be replaced with switches that support VSF to support the required distance between stack members.
  • When the VSF commander fails, it must initiate a graceful restart.
  • That the domain ID matches on both switches.

Other Configurations

  • BPDU protection blocks a port if it receives any BPDU, but root guard blocks a port only if the BPDU.
  • In the connectivity status between Switch-1 and Switch-2.
  • Both A1 and A2 block traffic.
  • M4 remains commander, M5 remains standby.
  • The standby becomes the commander of its fragment, which remains active. The fragment with the commander becomes inactive.
  • Leave SNMPv2c enabled, and enable SNMPv3 restricted access.
  • Link state update: It must run the shortest path first algorithm.
  • IGMP on VLAN 24; PIM-DM on VLAN 10.
  • When some guests successfully authenticate in the captive portal, they are redirected back to the portal page.
  • It drops multicasts destined to groups that have no members.
  • VLAN 20 must not enable jumbo frames.
  • VRRP takes longer than a second to fail over.
  • An issue with VLAN mismatch.
  • eBGP and iBGP administrative distance set to the same value.
  • It temporarily drops all IP traffic from Device 1 only.
  • Run a packet capture on Device 2.
  • A DSCP map that sets 46 to a priority value.
  • Endpoints in Area 1 will no longer be able to reach endpoints in other areas.
  • The VRID and the virtual IP address.
  • Change on branch switches: an SNMP trap.
  • It has no route to 192.168.2.1 in its IP routing table.
  • OSPF: BFD.
  • Physical Cable: UDLD.
  • It does not let users alter the URL that redirects them to the portal.
  • The mismatch between the chain names associated with VLAN 11 on Switch-1 and on Switch-3.
  • It forwards the traffic in VLAN 5.
  • Specify the voice setting in VLAN 3.
  • The standby uses its own port in the link aggregation to forward the fabric.
  • An 802.1p-to-DSCP map exists for priority 5.
  • A loop on the interface.
  • Graceful restart helper was not enabled on Switch-2, so BFD was unable to operate correctly, and the session was taken down.
  • All switches must use PIM-DM only or all switches must use PIM-SM only for the solution to work.
  • Due to changes at ISP 1, Switch-1 now selects a different best route 1.
  • It blocks the traffic, and it sends an SNMP trap.
  • 14625721022310321.
  • Set the switch to role-based tunneled node, and make sure it uses the default initial user role.
  • Switch-1 continues to act as it did before the preempt delay time was set. Administrators must plan additional changes to fix the issue.