Published on SecureTech Guides
Meta Description: Your router's logs hold secrets. Learn how to
access, read, and interpret your router's security logs in this step-by-step
2025-26 guide. Discover how to identify normal activity versus real threats
like intrusion attempts and unauthorized devices.
Keywords: router logs, check router logs, network intrusion,
unauthorized device, router security, network monitoring, detect hacker, WAN
access, firewall logs, connected devices
Introduction: The Security Camera You Didn't
Know You Had
After hardening your router with our previous
guide, you've built a strong fence. But a good security system doesn't just
have a fence—it has motion sensors and cameras to tell
you what's happening. Your router has these built-in; they're
called logs.
Most users never check these logs, leaving a
wealth of security intelligence untapped. In my work auditing networks, the
firewall and router logs are the first place I look to understand a network's
health and threat exposure. They provide a real-time ledger of every connection
attempt, block, and error.
This guide will transform that intimidating
wall of text and timestamps into a readable security report. I'll
show you where to find the logs on any router, teach you the key entries to
look for, and help you distinguish between harmless background noise and the
subtle signs of a real probe or intrusion attempt.
Part 1: Accessing Your Router's Logs – A
Universal Method
The first step is accessing your router's
admin panel, which you should already be familiar with from our previous guide.
1. Connect & Log In: Connect to your network (wired is best
for stability) and enter your router's IP address (e.g., 192.168.1.1) into a web browser. Log in with your secure
admin credentials.
2. Find the Log Section: The location varies by brand but is
typically under menus like:
o Advanced > System Log or Administration
Log
o Security > Logs
o Status > Logs
o Tools or Diagnostics
3. Enable Logging (If Needed): Some routers have logging disabled by
default. Look for an "Enable Logging" checkbox and
ensure it's turned on. You may also see options to log specific events
like WAN (Internet) access, Firewall blocks, or DHCP activity—enable
all security-related logs.
Pro Tip: If your router's interface is very basic and lacks
detailed logs, this is a compelling reason to consider upgrading to a more
capable router or a dedicated firewall (like the ones discussed in our Firewall
guide). Visibility is the foundation of control.
|
Log Field |
What It Tells You |
What to Look For |
|
Timestamp [2025-26-01-15 14:23:05] |
When the
event happened. |
Clustering of many events in a short time can indicate a
scan or attack. |
|
Action/Event Firewall: DROP or ACCEPT |
What the
router did. DROP/REJECT/ DENY means it blocked
something. ACCEPT means it allowed it. |
Frequent DROP events from the WAN
(Internet side) are good—your firewall is working. |
|
Source IP (SRC) SRC=104.18.22.45 |
The IP address the traffic came from. |
Is it from the WAN (Internet, like
104.18.22.45) or LAN (your local network, like
192.168.1.50)? WAN IPs are external. |
|
Destination IP (DST) DST=192.168.1.105 |
The IP address the traffic was sent to inside
your network. |
Which of your devices (e.g., your laptop at .105) was the
target? |
|
Port Number DPT=443 or SPT=5353 |
The "door number" the traffic was trying to
use. DPT is Destination Port, SPT is Source
Port. |
Common ports: 80 (HTTP), 443 (HTTPS), 22 (SSH), 3389 (Remote Desktop). Attacks often target specific
ports. |
Part 2: Decoding the Logs – What Do These
Entries Actually Mean?
A typical log entry looks like this:
[2025-01-15 14:23:05] Firewall: DROP IN=eth0 OUT= MAC=...
SRC=104.18.22.45 DST=192.168.1.105 LEN=40...
Don't be intimidated. Let's break down the
critical components:
Part 3: The Threat Matrix – Normal Noise vs.
Red Flags
To effectively monitor, you must know what's
normal. Here is my professional breakdown:
Category 1: Normal, Harmless Background Noise
(Don't Panic)
- Occasional
DROPs from WAN: The internet is
constantly scanned by bots. A few random DROP entries per hour is
standard.
- DHCP
Requests: Your devices requesting
or renewing their IP addresses (DHCP ACK, DHCP REQUEST).
- Local
Multicast/Broadcast Traffic: Devices
on your local network discovering each other (e.g., SRC=192.168.1.50, DST=224.0.0.251).
Category 2: Yellow Flags – Investigate Further
- Repeated
DROPs from the same WAN IP: This could be a targeted scan. Note the IP and
time.
- Attempts
on specific high-risk ports: Many
blocked attempts on port 22 (SSH), 23 (Telnet), 445 (SMB file sharing), or 3389 (RDP) from the WAN.
- Unknown
MAC or IP on your LAN: Check
your router's "Attached Devices" or "DHCP Client
List." If you see a device you don't recognize (e.g., a strange
manufacturer name like "Xiamoi" if you don't own Xiaomi
products), investigate immediately.
Category 3: Red Flags – Potential Intrusion or
Problem
- ACCEPT
entries for unsolicited WAN traffic: This
is critical. If you see an ACCEPT from
a WAN IP to a LAN device on a port you didn't intentionally open (like
port 22 or 3389), something may be misconfigured (e.g., port forwarding,
UPnP).
- Massive
volume of logs in minutes: A
flood of entries, especially DROPs, indicates a Denial-of-Service (DoS)
probe or an intense scan.
- Your
device contacting suspicious external IPs: If your laptop (SRC=192.168.1.105) is shown making outbound connections to known
malicious IPs (you can paste the IP into a site like VirusTotal.com to
check), it might be infected with malware.
Part 4: Your 5-Minute Weekly Security Audit
Routine
Turn log reading from a chore into a quick,
powerful habit.
1. Access Logs: Log into your router and navigate to the system/security
logs.
2. Filter for WAN DROPs: Quickly scan for recent DROP actions with a WAN (external)
Source IP. A healthy amount confirms your firewall is active.
3. Check for LAN ACCEPTs: Briefly look for any ACCEPT actions from the WAN. There should be
very few unless you're hosting a game or web server.
4. Cross-reference Connected Devices: Open the "Attached Devices"
list. Verify every device matches one you own (e.g., "John's iPhone,"
"Living-Room-TV," "Work-Laptop"). Any unknown device is a
priority investigation.
5. Look for Patterns: Are there 50 DROPs from IP 185.220.101.34 in the last hour? That's a scan. It's
blocked, but worth noting.
Actionable Response Plan:
- For
an unknown local device: Immediately
change your Wi-Fi password. This will disconnect all devices, forcing you
to reconnect only trusted ones.
- For
a suspicious WAN scan: You
can often add that specific IP to a firewall block list in
your router if it's persistent.
- For
any ACCEPT on a risky port: Revisit
your router's Port Forwarding and UPnP settings
to ensure they are disabled or correctly configured.
Conclusion: From Passive Defense to Active
Awareness
Checking your router logs is the difference
between hoping you're safe and knowing you're secure. It
transforms your router from a silent box into an active sentinel that reports
its defensive actions directly to you.
By spending just five minutes a week on this
routine, you gain profound insight into the threat landscape of your own home
network. You'll catch misconfigurations, spot aggressive scanners, and have the
peace of mind that comes from verified security.
Your Next Step: After implementing this, consider the
ultimate step in network visibility: setting up a dedicated network
monitoring tool or a SIEM for home use. But first, master
the fundamentals in the logs you already own.
Stay vigilant,
Muhammad Shafqat Hanif Dar
Senior Manager, Information Security & Founder of SecureTech Guides
*CISSO, Fortinet NSE 4-5, Sophos Certified Engineer*
