EOIP

In today’s world of networking technologies, combining two remote offices into a single entity is a fairly routine task. Usually, L3 tunnels are used for this (for example, IPIP or IPsec). However, there are situations when simple routing is not enough and full L2 connectivity is required, as if remote devices were connected to the same switch.

Let’s figure out when this is necessary and how to configure such connectivity correctly so that it is not only working but also fault-tolerant.

The EoIP (Ethernet over IP) protocol from MikroTik is used to create an L2 tunnel over an IP network, allowing you to combine two remote local networks into a single broadcast domain.
If your EoIP tunnel does not establish (no “R” — Running flag), follow this step-by-step checklist.

1. Check IP connectivity (L3)

Before starting, make sure the routers see each other at the IP level.

Ping the remote side:

This article is compiled as a “cheat sheet” for SOHO/SMB networks: common issues, their symptoms, causes, quick fixes, and diagnostic checklists. Suitable for both engineers and admins who maintain the MikroTik ↔ Keenetic bundle.

📑 Navigation

• EoIP “freezes” when transferring large files
• Site-to-Site VPN is up, but traffic doesn’t pass
• NAT breaks VPN/EoIP
• MTU/MSS: how to choose correctly
• Policy Routing (RouterOS 7)
• SMB from another subnet doesn’t work
• Quick diagnostics checklist
• Command cheat sheet
• Typical MTUs for tunnels
• NAT/Firewall exceptions matrix
• Common pitfalls
• Visualizations
• Resources and documentation

1) EoIP “freezes” when transferring large files

Symptoms: SMB/FTP hangs, speed fluctuates, RDP drops. Causes: incorrect MTU/MSS, fast-path with IPsec, NAT/Firewall errors.

Keenetic as a VPN Server: Secure Remote Access

The Remote Access Problem

When you’re away from home or the office, accessing local resources — such as a network-attached storage (NAS), server, or smart devices — can be challenging. Opening ports to the public internet is unsafe. The solution is to create a secure VPN tunnel, allowing you to safely connect to your local network from anywhere in the world. Keenetic makes this task simple by offering powerful and flexible VPN server functionality right out of the box.

In the world of networking, there’s often a need to bridge two remote LANs so they behave like a single local network—even when separated by different routers. For MikroTik users, the concept of EoIP (Ethernet over IP) is familiar: it’s a proprietary tunneling protocol that allows creation of a virtual Ethernet interface (Layer 2) over an IP network.

Good news for Keenetic users: since firmware NDMS v2.10, Keenetic routers also support EoIP! This opens up exciting possibilities for advanced network designs.