ip route tips — authorized routing-table literacy

Snapshot

Tip checklist (authorized only)

1. Confirm you may run ip route on the lab host (syllabus box you own or were given access to; some mutations need root/CAP).
2. Prefer documenting who / why / ticket before any route mutation — never change production default routes without change control.
3. Record short factual notes; quote short Evidence (destination + gateway + device — never secrets or tunnel keys).
4. Optional: address peer → ip-addr-tips.
5. Optional: classic route peer → route-tips.
6. Prefer disposable lab VMs and throwaway namespaces for route drills; quote non-secret labels afterward as Evidence.
7. Prefer ip route show / ip route get <dest> read-back before and after authorized changes — refuse unauthorized foreign-host cookbooks.
8. Stop at literacy — no attack or unauthorized route-bypass cookbooks.

Allowed framing

• Classroom labs reviewing ip route show / ip route get 8.8.8.8 on authorized disposable hosts.
• Binding short factual notes as Evidence (destination + gateway + device — no secrets).
• Documenting expected vs observed default/route table rows for authorized notes.
• Comparing ip-route ↔ ip-addr / route / ip-netns / ss / traceroute peer tip pages under one binder.
• Testing syllabus-approved lab-net route add/del only when change control authorizes that drill on lab resources.

Scope we will not cover

• No crack/pirate/keygen via ip route.
• No intentional unauthorized route injection against foreign hosts.
• No secret-theft or tunnel-key harvesting against hosts you do not own.
• No cookbooks that use route tables as an attack step against production without authorization.
• No ip route framed as a network-bypass against systems you do not own.

Beginner path (authorized only)

1. Obtain one syllabus-approved disposable lab host with iproute2 available.
2. Prefer a throwaway lab VM (or ip-netns-tips namespace) before any route-mutation drill.
3. With authorization, run ip route show then ip route get <lab-dest>; quote selected destination/gateway/device labels as Evidence.
4. Optional: peer tip pages above when the syllabus asks.
5. Stop at literacy — no attack or unauthorized route-bypass cookbooks.

Practical notes for authorized labs

• ip route shows the FIB — keep Evidence labels distinct from ip-addr-tips address listings.
• Pair with traceroute-tips when the syllabus zooms on path hops after a lab route change.
• ip route get is a great read-only drill — document selected dest/gateway/dev without dumping unrelated privileged state.
• Prefer documenting destination / gateway / device labels the syllabus authorized.
• Never commit route dumps with secrets, VPN PSK material, or proprietary tunnel endpoints to git — even for labs.

FAQ-aligned refusals (quick)

• Foreign-host route rewrite → refuse.
• Unauthorized route-bypass / hostile-injection attack cookbooks → refuse.
• Attack/credential-theft framing → refuse.

For legal, authorized and educational use only.

FAQ

Sources