pjhtech Tools
MikroTik

MikroTik LTE / 5G Troubleshooting

Fix an ignored manual APN on an MBIM modem, restore registration after a bad lock, or separate LTE service from LAN forwarding.

If LTE registers but has no data connection, check the active APN profile. On MBIM modems, use-network-apn=yes overrides a manually entered APN; set it to no when the operator requires your manual APN. If registration itself fails, use the SIM/operator checks below instead.

Read registration and the active APN

RouterOS 7
/system/resource/print
/interface/lte/print detail
/interface/lte/show-capabilities lte1
/interface/lte/monitor lte1 once
/interface/lte/apn/print detail
/log/print where topics~"lte"

Read version in the system resource output. Record modem model, firmware/revision, SIM status, registration and current operator from the LTE output. 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

For a PIN error, verify the SIM’s PIN with the provider before changing it; repeated guesses can block the SIM. For a registration rejection, confirm SIM activation and roaming permission. If registration stopped after a band/operator change, restore those recorded settings using the lock selection and removal guide.

Registered, but no usable Internet

After registration, compare the active profile named in apn-profiles with /interface/lte/apn/print detail. On an MBIM modem, use-network-apn=yes selects the network-provided APN, even when you entered a manual value. If the provider requires a manual APN, change the existing active profile as below. Replace both placeholders with the actual profile name and provider APN; preserve its existing authentication, user and password unless the provider requires a change. This can reconnect the data session.

RouterOS 7 · MBIM manual-APN correction
/interface/lte/apn/set [find where name="<active-profile>"] apn="<provider-APN>" use-network-apn=no
RouterOS 7
/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.

Replace the placeholder below with a known reachable Internet IP. On a multi-WAN router, verify the active route for that destination uses LTE before interpreting the result. A ping to this router’s own LAN address would test only the router itself.

RouterOS 7
/ping <known-reachable-Internet-IP> count=5
:put [:resolve "pjhtech.com"]

Registered, but slow

If the connection is registered but slow, compare a wired client transfer with the serving-cell and signal readings. If it became slow after a lock, remove that lock first and repeat the same transfer.

RouterOS 7
/interface/lte/monitor lte1 once
/interface/lte/cell-monitor lte1

Run cell-monitor only if cell-scan is supported, with an alternate access path. Stop it with Ctrl+C after collecting the sample. 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.

Check a modem firmware fix only for a matching defect

RouterOS 7 · supported MikroTik modem · check only
/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.

References