Use tcpdump for network diagnostics on Slackware

1. Goal

Quickly isolate ARP, DNS, port, or missing traffic issues with focused captures.

2. Files and components involved

/usr/sbin/tcpdump
/sbin/ip
/usr/bin/host

3. Operational flow

ip link show
tcpdump -ni eth0 arp
tcpdump -ni eth0 port 53
tcpdump -ni eth0 host 192.168.1.10

4. Operational verification

host slackware.com 127.0.0.1
ping -c 3 host
ss -lntup

5. Practical notes

Apply network changes from a local console or with an emergency session ready, so you do not lose SSH access.

Every network change should have a rollback path ready: a second console, KVM access, or a temporary command to remove.

Quick checklist

[ ] Backup or copy of the existing configuration completed
[ ] Files and commands updated as expected
[ ] Local test completed successfully
[ ] Logs or final output verified
[ ] Rollback procedure documented

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