MikroTik LTE / 5G Troubleshooting

1. Identify the modem and failure stage

/interface/lte/print detail
/interface/lte/show-capabilities lte1
/interface/lte/monitor lte1 once
/interface/lte/apn/print detail
/log/print where topics~"lte"

Record modem model, firmware/revision, RouterOS version, SIM status, registration and current operator. Redact IMSI, IMEI, ICCID, phone numbers and account details before sharing output. An interface being present is not proof of registration or an IP data session.

No registration

SIM/PIN → subscription and operator → supported RAT/bands → signal. Check SIM seating and activation; verify the PIN without repeated guesses. Confirm that operator or band locks have not excluded available service. Check roaming permission with the provider. APN is usually relevant to the data session after registration, but a registration success alone does not validate the APN.

Use the provider’s exact APN and authentication requirements. On supported MBIM modems, use-network-apn controls whether a network-provided APN is used; entering a manual APN while leaving that behavior active can mislead a test. Avoid changing unrelated radio settings until registration is understood.

Registered, but no usable Internet

/ip/address/print
/ip/route/print detail
/ip/dns/print
/ip/firewall/nat/print stats
/ip/firewall/filter/print stats

Look for an active route via LTE and confirm the APN’s add-default-route behavior and route distance. Test a known reachable IP before a DNS name. If the router works but LAN clients fail, inspect forwarding, source NAT, client gateway and DNS. In passthrough mode, the downstream host/router receives the cellular addressing; troubleshooting differs from a routed LAN.

Use a destination you operate or are authorized to test. The following first verifies the LAN gateway, then tests normal DNS resolution; it does not prove that the LTE Internet path is working by itself.

/ping 10.42.50.1 count=5
:put [:resolve "kernaali.fi"]

Registered, but slow

Signal quality → serving band and bandwidth → CA under load → time-of-day comparison → antenna trial → controlled band/cell trial. Strong RSRP cannot overcome poor SINR, congested scheduling or limited backhaul. Compare download, upload, loaded latency and packet loss. Test directly behind the cellular router so a busy Wi-Fi link is not mistaken for a cellular limit.

/interface/lte/monitor lte1 once
/interface/lte/cell-monitor lte1

Run cell-monitor only if cell-scan is supported, with an alternate access path. Collect EARFCN/PCI candidates and compare antenna positions. A modem may expose NR and CA details differently; do not interpret a missing field as proof the feature is inactive.

Firmware and rollback

/interface/lte/firmware-upgrade lte1 upgrade=no

This queries update availability where supported; it does not install firmware. Review the modem-specific update method and release notes before scheduling an upgrade. Do not power-cycle during firmware installation.

For rollback, restore the recorded APN, band lists, operator and RAT modes. Remove the cell lock with the command for that exact modem family. An empty band list does not remove a cell lock, and Safe Mode is not a dependable undo mechanism for modem-internal AT state.

Signal measurements · Band selection and reset · Cell-lock removal