This is also posted on the Apple’s Support Forum.
I found multiple similar questions but none of them helped me.
I have a home network with 2 machines connected to the Wi-Fi router. Ping from A to B fails on timeout. tcpdump shows that machine B does see the incoming requests. Ping from B to A works. Both machines run on Mac OS, firewalls disabled, tried connecting them using my Android phone's hotspot Wi-Fi with the same result.
I want to connect my laptop (MacBook) to the stationary PC (Mac mini) via remote desktop.
Router
- Model = Inteno DG400 Prime
- IP =
192.168.1.1 - AP Isolation = off
MacBook
OS = Catalina 10.15.6
IP =
192.168.1.231Firewall: off
pingworks on:localhost,127.0.0.1,192.168.1.1(router),192.168.1.231(itself)pingtimeouts on:192.168.1.185(mac mini)nslookup sams-mac-minisuccessfully resolves to192.168.1.185
netstat -rn:
Routing tables
Internet:
Destination Gateway Flags Netif Expire
default 192.168.1.1 UGSc en0
127 127.0.0.1 UCS lo0
127.0.0.1 127.0.0.1 UH lo0
169.254 link#6 UCS en0 !
192.168.1 link#6 UCS en0 !
192.168.1.1/32 link#6 UCS en0 !
192.168.1.1 20:1f:31:aa:e5:90 UHLWIir en0 1190
192.168.1.185 3c:22:fb:a8:43:ed UHLWI en0 902
192.168.1.231/32 link#6 UCS en0 !
224.0.0/4 link#6 UmCS en0 !
224.0.0.251 1:0:5e:0:0:fb UHmLWI en0
239.192.152.143 1:0:5e:40:98:8f UHmLWI en0
239.255.255.250 1:0:5e:7f:ff:fa UHmLWI en0
255.255.255.255/32 link#6 UCS en0 !
Internet6:
Destination Gateway Flags Netif Expire
default fe80::221f:31ff:feaa:e590%en0 UGc en0
default fe80::%utun0 UGcI utun0
default fe80::%utun1 UGcI utun1
default fe80::%utun2 UGcI utun2
default fe80::%utun3 UGcI utun3
::1 ::1 UHL lo0
2001:7d0:84b0:1580::/64 link#6 UC en0
2001:7d0:84b0:1580:4bf:ddc7:25f2:30f1 3c:22:fb:40:fd:5d UHL lo0
2001:7d0:84b0:1580:7c49:fd29:22b:1ea2 3c:22:fb:a8:43:ed UHLWIi en0
2001:7d0:84b0:1580:817a:55f7:e052:2518 link#6 UHLWI en0
2001:7d0:84b0:1580:bd28:6e56:8081:20c1 3c:22:fb:40:fd:5d UHL lo0
fe80::%lo0/64 fe80::1%lo0 UcI lo0
fe80::1%lo0 link#1 UHLI lo0
fe80::%en5/64 link#4 UCI en5
fe80::aede:48ff:fe00:1122%en5 ac:de:48:0:11:22 UHLI lo0
fe80::aede:48ff:fe33:4455%en5 ac:de:48:33:44:55 UHLWIi en5
fe80::%en0/64 link#6 UCI en0
fe80::c3d:9dc9:9593:12c8%en0 3c:22:fb:40:fd:5d UHLI lo0
fe80::1477:d6f9:e406:2a44%en0 3c:22:fb:a8:43:ed UHLWI en0
fe80::1826:bd30:ffca:e2af%en0 88:a9:b7:65:a0:4b UHLWI en0
fe80::221f:31ff:feaa:e590%en0 20:1f:31:aa:e5:90 UHLWIir en0
fe80::%awdl0/64 link#13 UCI awdl0
fe80::44ad:a1ff:febb:3021%awdl0 46:ad:a1:bb:30:21 UHLWIi awdl0
fe80::a861:11ff:fea8:3756%awdl0 aa:61:11:a8:37:56 UHLI lo0
fe80::%llw0/64 link#14 UCI llw0
fe80::44ad:a1ff:febb:3021%llw0 46:ad:a1:bb:30:21 UHLWI llw0
fe80::a861:11ff:fea8:3756%llw0 aa:61:11:a8:37:56 UHLI lo0
fe80::%utun0/64 fe80::e39:7f8:b2fb:4473%utun0 UcI utun0
fe80::e39:7f8:b2fb:4473%utun0 link#15 UHLI lo0
fe80::%utun1/64 fe80::245e:5d7e:31eb:6ac6%utun1 UcI utun1
fe80::245e:5d7e:31eb:6ac6%utun1 link#16 UHLI lo0
fe80::%utun2/64 fe80::4175:99b7:91f2:1a2e%utun2 UcI utun2
fe80::4175:99b7:91f2:1a2e%utun2 link#17 UHLI lo0
fe80::%utun3/64 fe80::19bd:c7d7:c780:8e80%utun3 UcI utun3
fe80::19bd:c7d7:c780:8e80%utun3 link#18 UHLI lo0
ff01::%lo0/32 ::1 UmCI lo0
ff01::%en5/32 link#4 UmCI en5
ff01::%en0/32 link#6 UmCI en0
ff01::%awdl0/32 link#13 UmCI awdl0
ff01::%llw0/32 link#14 UmCI llw0
ff01::%utun0/32 fe80::e39:7f8:b2fb:4473%utun0 UmCI utun0
ff01::%utun1/32 fe80::245e:5d7e:31eb:6ac6%utun1 UmCI utun1
ff01::%utun2/32 fe80::4175:99b7:91f2:1a2e%utun2 UmCI utun2
ff01::%utun3/32 fe80::19bd:c7d7:c780:8e80%utun3 UmCI utun3
ff02::%lo0/32 ::1 UmCI lo0
ff02::%en5/32 link#4 UmCI en5
ff02::%en0/32 link#6 UmCI en0
ff02::%awdl0/32 link#13 UmCI awdl0
ff02::%llw0/32 link#14 UmCI llw0
ff02::%utun0/32 fe80::e39:7f8:b2fb:4473%utun0 UmCI utun0
ff02::%utun1/32 fe80::245e:5d7e:31eb:6ac6%utun1 UmCI utun1
ff02::%utun2/32 fe80::4175:99b7:91f2:1a2e%utun2 UmCI utun2
ff02::%utun3/32 fe80::19bd:c7d7:c780:8e80%utun3 UmCI utun3
Mac Mini
OS = Catalina 10.15.6
IP =
192.168.1.185Firewall: off
pingworks on:localhost,127.0.0.1,192.168.1.1(router),192.168.1.185(itself),192.168.1.231(MacBook)nslookup sams-mbpsuccessfully resolves to192.168.1.231
Note: I do have a VPN installed but it's not connected/used at the moment, so you might see something here related to that.
netstat -rn:
Routing tables
Internet:
Destination Gateway Flags Netif Expire
default 192.168.1.1 UGSc en1
127 127.0.0.1 UCS lo0
127.0.0.1 127.0.0.1 UH lo0
169.254 link#7 UCS en1 !
192.168.1 link#7 UCS en1 !
192.168.1.1/32 link#7 UCS en1 !
192.168.1.1 20:1f:31:aa:e5:90 UHLWIir en1 1196
192.168.1.185/32 link#7 UCS en1 !
192.168.1.255 ff:ff:ff:ff:ff:ff UHLWbI en1 !
224.0.0/4 link#7 UmCS en1 !
224.0.0.251 1:0:5e:0:0:fb UHmLWI en1
239.255.255.250 1:0:5e:7f:ff:fa UHmLWI en1
255.255.255.255/32 link#7 UCS en1 !
Internet6:
Destination Gateway Flags Netif Expire
default fe80::221f:31ff:feaa:e590%en1 UGc en1
default fe80::%utun0 UGcI utun0
default fe80::%utun1 UGcI utun1
default fe80::%utun2 UGcI utun2
default fe80::%utun3 UGcI utun3
::1 ::1 UHL lo0
2001:7d0:84b0:1580::/64 link#7 UC en1
2001:7d0:84b0:1580:1c09:ef76:fc0f:6787 3c:22:fb:a8:43:ed UHL lo0
2001:7d0:84b0:1580:409c:597b:219b:31cd 3c:22:fb:a8:43:ed UHL lo0
2001:7d0:84b0:1580:8d39:c6a:9520:65a8 link#7 UHLWI en1
fe80::%lo0/64 fe80::1%lo0 UcI lo0
fe80::1%lo0 link#1 UHLI lo0
fe80::%en6/64 link#5 UCI en6
fe80::aede:48ff:fe00:1122%en6 ac:de:48:0:11:22 UHLI lo0
fe80::aede:48ff:fe33:4455%en6 ac:de:48:33:44:55 UHLWIi en6
fe80::%en1/64 link#7 UCI en1
fe80::1477:d6f9:e406:2a44%en1 3c:22:fb:a8:43:ed UHLI lo0
fe80::221f:31ff:feaa:e590%en1 20:1f:31:aa:e5:90 UHLWIir en1
fe80::%awdl0/64 link#9 UCI awdl0
fe80::5892:a4ff:fe11:f46c%awdl0 5a:92:a4:11:f4:6c UHLI lo0
fe80::a861:11ff:fea8:3756%awdl0 aa:61:11:a8:37:56 UHLWIi awdl0
fe80::%llw0/64 link#10 UCI llw0
fe80::5892:a4ff:fe11:f46c%llw0 5a:92:a4:11:f4:6c UHLI lo0
fe80::a861:11ff:fea8:3756%llw0 aa:61:11:a8:37:56 UHLWI llw0
fe80::%utun0/64 fe80::35c8:509b:4d5f:e060%utun0 UcI utun0
fe80::35c8:509b:4d5f:e060%utun0 link#16 UHLI lo0
fe80::%utun1/64 fe80::f4f5:d2b6:c69e:755e%utun1 UcI utun1
fe80::f4f5:d2b6:c69e:755e%utun1 link#17 UHLI lo0
fe80::%utun2/64 fe80::19c4:e545:e84:a3bc%utun2 UcI utun2
fe80::19c4:e545:e84:a3bc%utun2 link#18 UHLI lo0
fe80::%utun3/64 fe80::f9fd:1490:c5f0:37ef%utun3 UcI utun3
fe80::f9fd:1490:c5f0:37ef%utun3 link#20 UHLI lo0
ff01::%lo0/32 ::1 UmCI lo0
ff01::%en0/32 link#4 UmCI en0
ff01::%en6/32 link#5 UmCI en6
ff01::%en1/32 link#7 UmCI en1
ff01::%awdl0/32 link#9 UmCI awdl0
ff01::%llw0/32 link#10 UmCI llw0
ff01::%utun0/32 fe80::35c8:509b:4d5f:e060%utun0 UmCI utun0
ff01::%utun1/32 fe80::f4f5:d2b6:c69e:755e%utun1 UmCI utun1
ff01::%utun2/32 fe80::19c4:e545:e84:a3bc%utun2 UmCI utun2
ff01::%utun3/32 fe80::f9fd:1490:c5f0:37ef%utun3 UmCI utun3
ff02::%lo0/32 ::1 UmCI lo0
ff02::%en0/32 link#4 UmCI en0
ff02::%en6/32 link#5 UmCI en6
ff02::%en1/32 link#7 UmCI en1
ff02::%awdl0/32 link#9 UmCI awdl0
ff02::%llw0/32 link#10 UmCI llw0
ff02::%utun0/32 fe80::35c8:509b:4d5f:e060%utun0 UmCI utun0
ff02::%utun1/32 fe80::f4f5:d2b6:c69e:755e%utun1 UmCI utun1
ff02::%utun2/32 fe80::19c4:e545:e84:a3bc%utun2 UmCI utun2
ff02::%utun3/32 fe80::f9fd:1490:c5f0:37ef%utun3 UmCI utun3
Tests
Listen for ping requests on Mac mini:
Run
tcpdump -v host 192.168.1.231on Mac miniRun
ping -c 4 192.168.1.185on MacBookMac mini output:
tcpdump: data link type PKTAP tcpdump: listening on pktap, link-type PKTAP (Apple DLT_PKTAP), capture size 262144 bytes 11:43:05.797487 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.1.185 tell 192.168.1.231, length 28 11:43:05.797555 ARP, Ethernet (len 6), IPv4 (len 4), Reply 192.168.1.185 is-at 3c:22:fb:a8:43:ed (oui Unknown), length 28 11:43:05.814090 IP (tos 0x0, ttl 64, id 4572, offset 0, flags [none], proto ICMP (1), length 84) 192.168.1.231 > 192.168.1.185: ICMP echo request, id 40459, seq 0, length 64 11:43:06.734317 IP (tos 0x0, ttl 64, id 42401, offset 0, flags [none], proto ICMP (1), length 84) 192.168.1.231 > 192.168.1.185: ICMP echo request, id 40459, seq 1, length 64 11:43:07.722478 IP (tos 0x0, ttl 64, id 36241, offset 0, flags [none], proto ICMP (1), length 84) 192.168.1.231 > 192.168.1.185: ICMP echo request, id 40459, seq 2, length 64 11:43:08.726554 IP (tos 0x0, ttl 64, id 59095, offset 0, flags [none], proto ICMP (1), length 84) 192.168.1.231 > 192.168.1.185: ICMP echo request, id 40459, seq 3, length 64
MacBook got no responses, all 4 requests timed out but as you can see mac mini got all requests and seems to even respond to ARP but ICMP is left without a response.
Disabling IPv6
This gave me an idea it may be caused by Ipv6 so I ran networksetup -setv6off Wi-Fi on both machines which caused no changes, so I enabled it back.
Setting a manual IP for Mac mini
This suggests that if I set the IP of mac mini to something else in the DHCP pool it may do something but it didn't (I tried 192.168.1.230 and 192.168.1.232), so I put auto address back.
Disable other network interfaces
Reverse Path Filter seems extremely close to what I have but it's about Linux and Mac OS treats this differently. I didn't spend much time on this but I thought it's related to the machine being confused with network interfaces, so I disabled all of them except the 192.168.* on the mac mini but it didn't fix the problem.
Try a different router
I tried connecting the MacBook and the Mac Mini to my android phone's Wi-Fi hotspot but the situation is the same.
Connect via cable
I tried connecting the Mac Mini via ethernet cable directly into the router and nothing changed.
Hopefully, we can find a solution and it will even help somebody else in the future.
/etc/hostsis justASCII text, and I don't have Little Snitch installed but it wouldn't be a problem to install, not sure if it'll help though