About

Vivacom is a Bulgarian mobile network operator. Internet access over LTE and 5G is provided in dual-stack mode (IPv4 and IPv6).

As of May 2026, only Vivacom among the Bulgarian national operators provides dual-stack mobile connectivity (IPv4 and IPv6) for general internet access on typical consumer and business mobile data plans. A1 and Yettel are far behind on IPv6 adoption; their mobile plans do not currently include IPv6 internet access in a comparable form. That market position can change; treat this paragraph as a snapshot in time when planning coverage or failover.

This note describes how to give home clients global IPv6 on the LAN when the router uses Vivacom mobile data. Any MikroTik device with an LTE or 5G modem interface and RouterOS 7 can follow the same steps; examples use lte1 and ether1, which you should map to the default names on your model. Paths and property names match recent RouterOS; if a line is rejected, compare with print detail on your exact build.

Vivacom products and prefixes

Vivacom's default APN name for mobile internet access is internet (normal dual-stack consumer data).

Two different products exist on the same network, with different outcomes for your LAN.

  • Dynamic global /64: typical consumer PDP context. The prefix can change after a reboot or a new data session. IPv6 on the PDP context is provided via SLAAC on the path exposed by ipv6-interface.

  • Static global /64: requires a Vivacom contract that includes the mobix-static APN (or equivalent naming on your subscription). The operator assigns a fixed prefix suitable for a small site router.

For home LAN clients you normally want the operator /64 to appear on the LAN side of the router. On MikroTik LTE/5G this is done with the ipv6-interface parameter on an LTE APN profile, not by copying the WAN /64 onto another interface by hand.

Topology assumed here

  • WAN: lte1 (LTE/5G), member of interface list WAN.
  • LAN: the examples bind Vivacom IPv6 to ether1 via ipv6-interface. IPv4 and DHCP for the home network can live on ether1 directly, or on a bridge that contains ether1.

A bridge is not required for Vivacom IPv6 itself. It is only useful when you want one LAN segment that will later include other interfaces (for example a VPN tunnel interface) alongside ether1. In that case you create bridge1, add ether1 as a port, put LAN addressing on bridge1, and when the VPN exists you add the VPN interface as another bridge port so it shares the same LAN and the same RAs.

Adjust names if your setup differs.

Method: bind PDP IPv6 to the LAN port

The modem delivers IPv6 for the PDP context. The parameter ipv6-interface selects which local interface carries that /64 for addressing and router advertisement toward the LAN. On many single-Ethernet LTE/5G CPE layouts that port is ether1 facing the house switch or gateway; use whichever Ethernet port your hardware documentation recommends for ipv6-interface.

If you use a bridge for the LAN, ipv6-interface should still target the same bridge port (typically ether1) that MikroTik expects for the LTE IPv6 offload, and that port must be a member of the bridge so Wi‑Fi, VPN, and Ethernet share one L2 domain and the same router advertisements.

1. APN profiles

Create or edit profiles in /interface lte apn. You need at least one profile referenced by lte1 via apn-profiles.

Example for the default Vivacom APN internet, with IPv6 presented on ether1:

/interface lte apn add name=internet apn=internet ipv6-interface=ether1 use-network-apn=no add-default-route=yes use-peer-dns=yes authentication=none

Example for static service (only if your contract provides it), still binding IPv6 to ether1:

/interface lte apn add name=mobix-static apn=mobix-static ipv6-interface=ether1 use-network-apn=no add-default-route=yes use-peer-dns=yes authentication=none

If you already have a row named default, edit it instead of adding duplicates. Use a full selector, for example:

/interface lte apn set [find where name="default"] apn=internet ipv6-interface=ether1 use-network-apn=no

2. Point the LTE interface at the profile you want

/interface lte set [find where default-name="lte1"] apn-profiles=internet

For static prefix service, set apn-profiles to the profile whose apn= is mobix-static, for example:

/interface lte set [find where default-name="lte1"] apn-profiles=mobix-static

3. Optional: bridge the LAN for a future VPN (or other extra interfaces)

Skip this entire subsection if you are happy with a single LAN port and no bridge.

When you expect a site-to-site or road-warrior VPN interface to become part of the same home LAN as ether1, create a bridge now, attach ether1, attach IPv4 (and any DHCP server) to the bridge, and later add the VPN interface as another bridge port. Vivacom IPv6 still uses ipv6-interface=ether1; the prefix and RAs reach the whole bridge because ether1 is inside it.

/interface bridge add name=bridge1 protocol-mode=rstp
/interface bridge port add bridge=bridge1 interface=ether1

Put LAN IPv4 on bridge1 if you use the bridge; otherwise keep it on ether1. Do not rely on addressing the same global /64 on both lte1 and the LAN without this LTE ipv6-interface integration; that is not the supported model for Vivacom dynamic /64 on the UE.

4. Interface lists and defconf firewall

Keep lte1 on WAN. Put the interface that receives home traffic on LAN (bridge1 if you use a bridge, otherwise ether1). The default RouterOS IPv4/IPv6 firewall examples are compatible with working LAN IPv6 once ipv6-interface is correct.

5. Router advertisement timing (optional)

Global ND is under /ipv6 nd with interface=all on a default install. Shorter RA intervals reduce the time for clients to see a new prefix after LTE comes up, for example:

/ipv6 nd print detail
/ipv6 nd set 0 ra-interval=3s-10s ra-delay=1s ra-lifetime=30m

DNS in RA:

/ipv6 nd set 0 advertise-dns=yes

Prefix lifetimes after a reboot (dynamic service only)

Router advertisements and prefix lifetimes

For the LTE-managed dynamic prefix, RouterOS creates a row under /ipv6 nd prefix print detail with valid-lifetime=infinity and preferred-lifetime=infinity. That is the Prefix Information option your LAN hosts learn from router advertisements.

You cannot override those lifetimes on that row: any attempt to shorten them fails, for example:

/ipv6 nd prefix set 0 preferred-lifetime=30m valid-lifetime=2h

RouterOS returns can not change dynamic prefix. So the router does not offer a supported way, on this path, to advertise the same dynamic prefix with finite preferred or valid lifetimes. Tuning /ipv6 nd set for interface=all (ra-interval, ra-delay, ra-lifetime, and so on) changes how often RAs are sent and default-router timing; it does not replace finite prefix lifetimes in the Prefix Information option while the prefix row stays dynamic and locked.

Client-side address lifetimes

Hosts reflect those RAs in their own address state. On Linux, ip addr (or ip -6 addr show) lists global addresses with valid_lft forever and preferred_lft forever when the last RA used infinite prefix lifetimes. After Vivacom assigns a new /64 (for example after a router reboot), you can briefly have two global addresses in two different /64 prefixes on the same interface: the old one is still forever in the kernel until policy or user action clears it, whilst the new prefix also appears. That window is painful for connectivity when traffic still sources from the stale prefix.

Mitigation

A static /64 from the mobix-static (or current equivalent) product avoids surprise prefix changes, so the stale-prefix problem largely disappears. For dynamic service only, expect some client stacks to be slow; there is no RouterOS knob observed here to force finite prefix lifetimes on the dynamic ND prefix.

CLI traps that confuse people

  • The word default is reserved in scripts; in finds prefer [find where name="default"] or set by numbers=0 from print.

  • Hyphenated values such as ipv4-ipv6 must be quoted in some contexts: ip-type="ipv4-ipv6". On many LTE builds only auto exists for ip-type; Vivacom IPv6 here is driven by ipv6-interface, not by guessing ip-type.

  • ? as interactive help may not work in your SSH client; use print detail and WinBox or WebFig to see properties.

Quick verification

/interface lte apn print detail
/interface lte print detail
/ipv6 address print detail
/ipv6 nd prefix print detail

You should see a global /64 on the LAN path (ether1, or bridge1 if the bridge carries the RA) consistent with Vivacom, and an ND prefix row for that LAN interface with autonomous=yes for SLAAC.

Summary

Goal Vivacom requirement MikroTik lever
IPv6 on home LAN with dynamic /64 Normal data APN (internet, Vivacom default) ipv6-interface=ether1 (or the LAN port your modem supports) on the active APN profile; lte1 apn-profiles pointing at that profile; optional bridge1 containing ether1 if you plan VPN or other ports on the same LAN
Same, but prefix stable across reboots Contract with mobix-static (or current Vivacom static product name) Same ipv6-interface pattern; apn-profiles selects the mobix-static profile

This document reflects lab and field behaviour for Vivacom LTE/5G on MikroTik routers with RouterOS 7; Vivacom may rename APNs or products. Confirm the exact APN string and static product name on your order form or with Vivacom business support before raising tickets.