IPv4 vs IPv6: The Real Differences
IPv4 vs IPv6 in 2026. Header differences, ARP vs Neighbor Discovery, SLAAC vs DHCP, NAT vs end-to-end, and dual-stack as the migration reality.
Archive
Latest posts — page 50
IPv6 Address Format Explained Byte by Byte
IPv6 addresses are 128 bits as eight groups of four hex digits. The two compression rules, prefix notation, EUI-64 interface IDs, special addresses, and worked examples.
HSRP vs VRRP vs GLBP: All Three Running Side by Side
Most FHRP comparisons are a table and nothing else. This one runs HSRP, VRRP and GLBP at the same time on the same two routers, so you can read Active/Standby against MASTER/BACKUP against AVG/AVF, decode each protocol's virtual MAC, and watch GLBP keep both routers forwarding for one virtual...
GLBP for Active/Active Load Balancing
GLBP (Gateway Load Balancing Protocol) is Cisco's load-balancing FHRP. AVG, AVFs, three load balancing methods, configuration, and when GLBP is actually the right answer.
VRRP Explained: The Vendor-Neutral FHRP
VRRP (Virtual Router Redundancy Protocol, RFC 5798) is the vendor-neutral FHRP. How it works, master election, IP address owner trap, vs HSRP, Cisco IOS XE configuration, and tracking.
Cisco MPLS Configuration on IOS XE
Cisco MPLS configuration on IOS XE: enabling MPLS forwarding, LDP, LDP-IGP sync, VRFs for L3VPN, and MP-BGP between PEs. With a complete PE config example.
MPLS L3VPN with MP-BGP and VPNv4
MPLS L3VPN architecture: VRFs, Route Distinguishers, Route Targets, MP-BGP for VPNv4, the two-label stack, PE-CE routing, and the Cisco IOS XE configuration.
LDP and MPLS Label Distribution
LDP (Label Distribution Protocol) distributes MPLS labels across the network. Discovery, session establishment, distribution and retention modes, LDP-IGP sync, and Cisco IOS XE configuration.
MPLS Labels Explained: Format, Stacking, and Penultimate Hop Popping
MPLS labels byte-by-byte: 20-bit label, EXP/TC, S bit, TTL. The label stack model, reserved labels, Penultimate Hop Popping, TTL handling, and what labels look like in Wireshark.
EIGRP Stub Routing for Hub-and-Spoke
EIGRP stub routing makes hub-and-spoke topologies scale. The five stub options, query suppression, DMVPN integration, and the production patterns for branch deployments.
EIGRP vs OSPF: When to Use Each
EIGRP vs OSPF in 2026. The technical differences, the convergence story, vendor reality (EIGRP is still Cisco-only in practice), and the design implications for new vs existing networks.
EIGRP Configuration on Cisco IOS XE: Classic and Named Mode
EIGRP configuration on Cisco IOS XE: classic mode, named mode, network statements, passive-interface default, summarization, HMAC-SHA-256 authentication, and the production template.