NAT and ARP Changes in Repeater Setup | Generated by AI
NETWORK TOPOLOGY — AFTER ROUTER A CONNECTED
=============================================
BEFORE (single router):
Internet → Router B (China Telecom Gateway, .1) → all devices
NOW (repeater setup):
Internet → Router A (TP-LINK, .37) ~wireless repeater~ Router B (.1) → devices
↓ ↓
Devices behind A Devices on B's WiFi
WHAT CHANGED IN ARP TABLE:
.37 appeared — Router A (TP-LINK)
MAC: locally administered, "permanent" flag
Latency: 2ms (very close — it's the router itself)
.36, .18, .19, .20 now share the SAME MAC address
→ These devices are behind Router A, NAT'd through it
→ Router A rewrites their MACs to its own
.14, .21, .24, .26, .31, .50, .54 kept their original MACs
→ Still connected directly to Router B's WiFi
DEVICE CLASSIFICATION:
BEHIND ROUTER A (TP-LINK, NAT'd):
.36 Workstation (ASRock, wired to Router A)
.18 TP-LINK device (IoT/smart home?)
.19 unknown
.20 Intel device
ON ROUTER B (China Telecom, direct):
.1 Router B itself
.14 Xiaomi
.21 Apple private WiFi
.24 Apple private WiFi
.26 unknown (50:8b:b9)
.31 Apple private WiFi
.50 unknown (34:55:06)
.54 Apple private WiFi
DISAPPEARED (were on B, now gone):
.42, .49, .52, .53 — phones/tablets went to sleep
.52 was your Air, but now shows as .37's network
NOTE: Your Air (.52) is connected to Router B's WiFi
but ARP shows it talking through Router A's MAC
→ Air is on Router B's side, not behind Router A
The repeater creates two logical zones. Devices behind Router A get NAT’d (same MAC in ARP). Devices on Router B keep their real MACs. Your workstation (.36) is wired to Router A — that’s why it appears NAT’d.