Hi Everyone!
I have a Ubuntu 20.04 LTS box installed with the following network configuration: *Internet/ISP* ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 209.249.157.70 netmask 255.255.255.248 broadcast 209.249.157.71 inet6 fe80::250:56ff:feb7:eeb6 prefixlen 64 scopeid 0x20<link> ether 00:50:56:b7:ee:b6 txqueuelen 1000 (Ethernet) RX packets 7916 bytes 544678 (544.6 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 975 bytes 184556 (184.5 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
*HAM Network* ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 44.135.100.10 netmask 255.255.255.248 broadcast 44.135.100.15 inet6 fe80::250:56ff:feb7:57ba prefixlen 64 scopeid 0x20<link> ether 00:50:56:b7:57:ba txqueuelen 1000 (Ethernet) RX packets 35 bytes 2558 (2.5 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 37 bytes 3152 (3.1 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 104 bytes 8024 (8.0 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 104 bytes 8024 (8.0 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
*AMPRNet IPIP* tunl0: flags=4289<UP,RUNNING,NOARP,MULTICAST> mtu 1480 inet 44.135.100.9 netmask 255.255.255.255 tunnel txqueuelen 1000 (IPIP Tunnel) RX packets 37 bytes 17484 (17.4 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 5 bytes 260 (260.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Machines on my "ham" network (44.135.100.8/29 - interface ens192) can only communicate within the routes I receive via rip44. Is this normal?
For example, from a machine on the ham network (ens192), I can connect to va3emt-1.ampr.org (44.135.87.1) but cannot ping 8.8.8.8 (google dns). A tcpdump shows its going out the wrong interface (ens160).
Also, from my ISP, I can ping 44.135.87.1 (and retrieve the web page) but I cannot ping or access 44.135.100.9,10,11,etc ....
Here are my commands I'm using to connect:
ip tunnel add tunl0 mode ipip local 209.249.157.70 ttl 255 ip link set dev tunl0 up ifconfig tunl0 up 44.135.100.9 netmask 255.255.255.255 multicast ip rule add to 44.0.0.0/9 table 44 priority 44 ip rule add to 44.128.0.0/10 table 44 priority 44 ip rule add from 44.135.100.8/29 table 44 priority 45 ip route add default dev tunl0 via 169.228.34.84 onlink table 44 ip route add 44.135.100.8/29 dev ens192 table 44 /usr/sbin/ampr-ripd -s -r -t 44 -i tunl0 -a 44.135.100.8/29 -d -v
Any ideas?
Ian.
Some debug: root@ampr-router:~# ip rule 0: from all lookup local 44: from all to 44.0.0.0/9 lookup 44 44: from all to 44.128.0.0/10 lookup 44 45: from 44.135.100.8/29 lookup 44 32766: from all lookup main 32767: from all lookup default
root@ampr-router:~# ip route show default via 209.249.157.65 dev ens160 proto static 44.135.100.8/29 dev ens192 proto kernel scope link src 44.135.100.10 209.249.157.64/29 dev ens160 proto kernel scope link src 209.249.157.70
root@ampr-router:~# ip route show table 44 | more default via 169.228.34.84 dev tunl0 onlink 44.0.0.1 via 169.228.34.84 dev tunl0 proto 44 onlink window 840 44.2.0.1 via 191.183.136.1 dev tunl0 proto 44 onlink window 840 44.2.0.2 via 98.20.210.138 dev tunl0 proto 44 onlink window 840 44.2.0.3 via 36.83.94.245 dev tunl0 proto 44 onlink window 840 44.2.2.0/24 via 216.218.207.198 dev tunl0 proto 44 onlink window 840 44.2.7.0/30 via 73.116.117.178 dev tunl0 proto 44 onlink window 840 44.2.10.0/29 via 104.49.12.130 dev tunl0 proto 44 onlink window 840 44.2.11.8/29 via 47.33.29.119 dev tunl0 proto 44 onlink window 840 44.2.50.0/29 via 50.63.202.93 dev tunl0 proto 44 onlink window 840 44.4.0.48/28 via 107.3.166.19 dev tunl0 proto 44 onlink window 840 44.4.2.152/29 via 173.167.109.217 dev tunl0 proto 44 onlink window 840 ..... alot of routes here ..... 44.185.66.0/24 via 89.106.108.151 dev tunl0 proto 44 onlink window 840 44.185.69.0/24 via 80.80.140.38 dev tunl0 proto 44 onlink window 840 44.185.80.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.92.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.96.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.103.0/24 via 89.190.200.249 dev tunl0 proto 44 onlink window 840 44.185.104.0/24 via 178.254.198.205 dev tunl0 proto 44 onlink window 840 44.185.105.0/24 via 91.139.210.119 dev tunl0 proto 44 onlink window 840 44.185.106.0/24 via 95.158.166.222 dev tunl0 proto 44 onlink window 840 44.185.107.0/24 via 77.70.122.201 dev tunl0 proto 44 onlink window 840 44.185.108.0/27 via 78.83.56.107 dev tunl0 proto 44 onlink window 840 44.185.109.0/24 via 91.92.93.15 dev tunl0 proto 44 onlink window 840 44.188.1.1 via 70.80.196.6 dev tunl0 proto 44 onlink window 840 44.188.192.222 via 176.67.24.190 dev tunl0 proto 44 onlink window 840 44.224.0.0/15 via 141.75.245.225 dev tunl0 proto 44 onlink window 840
Hi Ian,
You need to contact your coordinator and have him add reverse dns entries for your subnet into the ampr dns zones. Without reverse dns entries for the hosts, they are blocked from accessing the internet.
Ruben - ON3RVH
On 5 Jul 2020, at 08:49, Ian Redden via 44Net 44net@mailman.ampr.org wrote:
Hi Everyone!
I have a Ubuntu 20.04 LTS box installed with the following network configuration: *Internet/ISP* ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 209.249.157.70 netmask 255.255.255.248 broadcast 209.249.157.71 inet6 fe80::250:56ff:feb7:eeb6 prefixlen 64 scopeid 0x20<link> ether 00:50:56:b7:ee:b6 txqueuelen 1000 (Ethernet) RX packets 7916 bytes 544678 (544.6 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 975 bytes 184556 (184.5 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
*HAM Network* ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 44.135.100.10 netmask 255.255.255.248 broadcast 44.135.100.15 inet6 fe80::250:56ff:feb7:57ba prefixlen 64 scopeid 0x20<link> ether 00:50:56:b7:57:ba txqueuelen 1000 (Ethernet) RX packets 35 bytes 2558 (2.5 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 37 bytes 3152 (3.1 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 104 bytes 8024 (8.0 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 104 bytes 8024 (8.0 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
*AMPRNet IPIP* tunl0: flags=4289<UP,RUNNING,NOARP,MULTICAST> mtu 1480 inet 44.135.100.9 netmask 255.255.255.255 tunnel txqueuelen 1000 (IPIP Tunnel) RX packets 37 bytes 17484 (17.4 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 5 bytes 260 (260.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Machines on my "ham" network (44.135.100.8/29 - interface ens192) can only communicate within the routes I receive via rip44. Is this normal?
For example, from a machine on the ham network (ens192), I can connect to va3emt-1.ampr.org (44.135.87.1) but cannot ping 8.8.8.8 (google dns). A tcpdump shows its going out the wrong interface (ens160).
Also, from my ISP, I can ping 44.135.87.1 (and retrieve the web page) but I cannot ping or access 44.135.100.9,10,11,etc ....
Here are my commands I'm using to connect:
ip tunnel add tunl0 mode ipip local 209.249.157.70 ttl 255 ip link set dev tunl0 up ifconfig tunl0 up 44.135.100.9 netmask 255.255.255.255 multicast ip rule add to 44.0.0.0/9 table 44 priority 44 ip rule add to 44.128.0.0/10 table 44 priority 44 ip rule add from 44.135.100.8/29 table 44 priority 45 ip route add default dev tunl0 via 169.228.34.84 onlink table 44 ip route add 44.135.100.8/29 dev ens192 table 44 /usr/sbin/ampr-ripd -s -r -t 44 -i tunl0 -a 44.135.100.8/29 -d -v
Any ideas?
Ian.
Some debug: root@ampr-router:~# ip rule 0: from all lookup local 44: from all to 44.0.0.0/9 lookup 44 44: from all to 44.128.0.0/10 lookup 44 45: from 44.135.100.8/29 lookup 44 32766: from all lookup main 32767: from all lookup default
root@ampr-router:~# ip route show default via 209.249.157.65 dev ens160 proto static 44.135.100.8/29 dev ens192 proto kernel scope link src 44.135.100.10 209.249.157.64/29 dev ens160 proto kernel scope link src 209.249.157.70
root@ampr-router:~# ip route show table 44 | more default via 169.228.34.84 dev tunl0 onlink 44.0.0.1 via 169.228.34.84 dev tunl0 proto 44 onlink window 840 44.2.0.1 via 191.183.136.1 dev tunl0 proto 44 onlink window 840 44.2.0.2 via 98.20.210.138 dev tunl0 proto 44 onlink window 840 44.2.0.3 via 36.83.94.245 dev tunl0 proto 44 onlink window 840 44.2.2.0/24 via 216.218.207.198 dev tunl0 proto 44 onlink window 840 44.2.7.0/30 via 73.116.117.178 dev tunl0 proto 44 onlink window 840 44.2.10.0/29 via 104.49.12.130 dev tunl0 proto 44 onlink window 840 44.2.11.8/29 via 47.33.29.119 dev tunl0 proto 44 onlink window 840 44.2.50.0/29 via 50.63.202.93 dev tunl0 proto 44 onlink window 840 44.4.0.48/28 via 107.3.166.19 dev tunl0 proto 44 onlink window 840 44.4.2.152/29 via 173.167.109.217 dev tunl0 proto 44 onlink window 840 ..... alot of routes here ..... 44.185.66.0/24 via 89.106.108.151 dev tunl0 proto 44 onlink window 840 44.185.69.0/24 via 80.80.140.38 dev tunl0 proto 44 onlink window 840 44.185.80.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.92.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.96.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.103.0/24 via 89.190.200.249 dev tunl0 proto 44 onlink window 840 44.185.104.0/24 via 178.254.198.205 dev tunl0 proto 44 onlink window 840 44.185.105.0/24 via 91.139.210.119 dev tunl0 proto 44 onlink window 840 44.185.106.0/24 via 95.158.166.222 dev tunl0 proto 44 onlink window 840 44.185.107.0/24 via 77.70.122.201 dev tunl0 proto 44 onlink window 840 44.185.108.0/27 via 78.83.56.107 dev tunl0 proto 44 onlink window 840 44.185.109.0/24 via 91.92.93.15 dev tunl0 proto 44 onlink window 840 44.188.1.1 via 70.80.196.6 dev tunl0 proto 44 onlink window 840 44.188.192.222 via 176.67.24.190 dev tunl0 proto 44 onlink window 840 44.224.0.0/15 via 141.75.245.225 dev tunl0 proto 44 onlink window 840 _________________________________________ 44Net mailing list 44Net@mailman.ampr.org https://mailman.ampr.org/mailman/listinfo/44net
Hello;
The Canadian Coordinator (Luc) setup the reverse DNS for a few IP's, but still having the same issue.
On my 44.135.100.64 box (alpha.va3ian.ampr.org), I ping 8.8.8.8:
# tcpdump -vvv -i ens160 -s0 -n proto ipencap tcpdump: listening on ens160, link-type EN10MB (Ethernet), capture size 262144 bytes 04:06:20.335949 IP (tos 0x0, ttl 64, id 35897, offset 0, flags [DF], proto IPIP (4), length 104) 209.249.157.70 > 169.228.34.84: IP (tos 0x0, ttl 63, id 11140, offset 0, flags [DF], proto ICMP (1), length 84) 44.135.100.64 > 8.8.8.8: ICMP echo request, id 2198, seq 4, length 64 04:06:21.359937 IP (tos 0x0, ttl 64, id 35904, offset 0, flags [DF], proto IPIP (4), length 104) 209.249.157.70 > 169.228.34.84: IP (tos 0x0, ttl 63, id 11371, offset 0, flags [DF], proto ICMP (1), length 84) 44.135.100.64 > 8.8.8.8: ICMP echo request, id 2198, seq 5, length 64 04:06:22.383955 IP (tos 0x0, ttl 64, id 36075, offset 0, flags [DF], proto IPIP (4), length 104) 209.249.157.70 > 169.228.34.84: IP (tos 0x0, ttl 63, id 11534, offset 0, flags [DF], proto ICMP (1), length 84) 44.135.100.64 > 8.8.8.8: ICMP echo request, id 2198, seq 6, length 64 04:06:23.407933 IP (tos 0x0, ttl 64, id 36281, offset 0, flags [DF], proto IPIP (4), length 104) 209.249.157.70 > 169.228.34.84: IP (tos 0x0, ttl 63, id 11621, offset 0, flags [DF], proto ICMP (1), length 84) 44.135.100.64 > 8.8.8.8: ICMP echo request, id 2198, seq 7, length 64
Something is still blocking the communication coming back... no ICMP echo reply.
Same, but to 44.135.87.1: # tcpdump -vvv -i ens160 -s0 -n proto ipencap tcpdump: listening on ens160, link-type EN10MB (Ethernet), capture size 262144 bytes 04:08:08.874899 IP (tos 0x0, ttl 64, id 64044, offset 0, flags [DF], proto IPIP (4), length 104) 209.249.157.70 > 216.46.157.231: IP (tos 0x0, ttl 63, id 10835, offset 0, flags [DF], proto ICMP (1), length 84) 44.135.100.64 > 44.135.87.1: ICMP echo request, id 2200, seq 6, length 64 04:08:08.900877 IP (tos 0x0, ttl 52, id 35798, offset 0, flags [DF], proto IPIP (4), length 104) 216.46.157.231 > 209.249.157.70: IP (tos 0x0, ttl 64, id 53707, offset 0, flags [none], proto ICMP (1), length 84) 44.135.87.1 > 44.135.100.64: ICMP echo reply, id 2200, seq 6, length 64 04:08:09.876445 IP (tos 0x0, ttl 64, id 64228, offset 0, flags [DF], proto IPIP (4), length 104) 209.249.157.70 > 216.46.157.231: IP (tos 0x0, ttl 63, id 10977, offset 0, flags [DF], proto ICMP (1), length 84) 44.135.100.64 > 44.135.87.1: ICMP echo request, id 2200, seq 7, length 64 04:08:09.902369 IP (tos 0x0, ttl 52, id 36030, offset 0, flags [DF], proto IPIP (4), length 104) 216.46.157.231 > 209.249.157.70: IP (tos 0x0, ttl 64, id 53800, offset 0, flags [none], proto ICMP (1), length 84) 44.135.87.1 > 44.135.100.64: ICMP echo reply, id 2200, seq 7, length 64 04:08:10.877958 IP (tos 0x0, ttl 64, id 64382, offset 0, flags [DF], proto IPIP (4), length 104) 209.249.157.70 > 216.46.157.231: IP (tos 0x0, ttl 63, id 11074, offset 0, flags [DF], proto ICMP (1), length 84) 44.135.100.64 > 44.135.87.1: ICMP echo request, id 2200, seq 8, length 64 04:08:10.903853 IP (tos 0x0, ttl 52, id 36106, offset 0, flags [DF], proto IPIP (4), length 104) 216.46.157.231 > 209.249.157.70: IP (tos 0x0, ttl 64, id 53971, offset 0, flags [none], proto ICMP (1), length 84) 44.135.87.1 > 44.135.100.64: ICMP echo reply, id 2200, seq 8, length 64
Any help is greatly appreciated.
Ian.
On Sun, Jul 5, 2020 at 2:47 AM Ian Redden iredden@gmail.com wrote:
Hi Everyone!
I have a Ubuntu 20.04 LTS box installed with the following network configuration: *Internet/ISP* ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 209.249.157.70 netmask 255.255.255.248 broadcast 209.249.157.71 inet6 fe80::250:56ff:feb7:eeb6 prefixlen 64 scopeid 0x20<link> ether 00:50:56:b7:ee:b6 txqueuelen 1000 (Ethernet) RX packets 7916 bytes 544678 (544.6 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 975 bytes 184556 (184.5 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
*HAM Network* ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 44.135.100.10 netmask 255.255.255.248 broadcast 44.135.100.15 inet6 fe80::250:56ff:feb7:57ba prefixlen 64 scopeid 0x20<link> ether 00:50:56:b7:57:ba txqueuelen 1000 (Ethernet) RX packets 35 bytes 2558 (2.5 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 37 bytes 3152 (3.1 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 104 bytes 8024 (8.0 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 104 bytes 8024 (8.0 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
*AMPRNet IPIP* tunl0: flags=4289<UP,RUNNING,NOARP,MULTICAST> mtu 1480 inet 44.135.100.9 netmask 255.255.255.255 tunnel txqueuelen 1000 (IPIP Tunnel) RX packets 37 bytes 17484 (17.4 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 5 bytes 260 (260.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Machines on my "ham" network (44.135.100.8/29 - interface ens192) can only communicate within the routes I receive via rip44. Is this normal?
For example, from a machine on the ham network (ens192), I can connect to va3emt-1.ampr.org (44.135.87.1) but cannot ping 8.8.8.8 (google dns). A tcpdump shows its going out the wrong interface (ens160).
Also, from my ISP, I can ping 44.135.87.1 (and retrieve the web page) but I cannot ping or access 44.135.100.9,10,11,etc ....
Here are my commands I'm using to connect:
ip tunnel add tunl0 mode ipip local 209.249.157.70 ttl 255 ip link set dev tunl0 up ifconfig tunl0 up 44.135.100.9 netmask 255.255.255.255 multicast ip rule add to 44.0.0.0/9 table 44 priority 44 ip rule add to 44.128.0.0/10 table 44 priority 44 ip rule add from 44.135.100.8/29 table 44 priority 45 ip route add default dev tunl0 via 169.228.34.84 onlink table 44 ip route add 44.135.100.8/29 dev ens192 table 44 /usr/sbin/ampr-ripd -s -r -t 44 -i tunl0 -a 44.135.100.8/29 -d -v
Any ideas?
Ian.
Some debug: root@ampr-router:~# ip rule 0: from all lookup local 44: from all to 44.0.0.0/9 lookup 44 44: from all to 44.128.0.0/10 lookup 44 45: from 44.135.100.8/29 lookup 44 32766: from all lookup main 32767: from all lookup default
root@ampr-router:~# ip route show default via 209.249.157.65 dev ens160 proto static 44.135.100.8/29 dev ens192 proto kernel scope link src 44.135.100.10 209.249.157.64/29 dev ens160 proto kernel scope link src 209.249.157.70
root@ampr-router:~# ip route show table 44 | more default via 169.228.34.84 dev tunl0 onlink 44.0.0.1 via 169.228.34.84 dev tunl0 proto 44 onlink window 840 44.2.0.1 via 191.183.136.1 dev tunl0 proto 44 onlink window 840 44.2.0.2 via 98.20.210.138 dev tunl0 proto 44 onlink window 840 44.2.0.3 via 36.83.94.245 dev tunl0 proto 44 onlink window 840 44.2.2.0/24 via 216.218.207.198 dev tunl0 proto 44 onlink window 840 44.2.7.0/30 via 73.116.117.178 dev tunl0 proto 44 onlink window 840 44.2.10.0/29 via 104.49.12.130 dev tunl0 proto 44 onlink window 840 44.2.11.8/29 via 47.33.29.119 dev tunl0 proto 44 onlink window 840 44.2.50.0/29 via 50.63.202.93 dev tunl0 proto 44 onlink window 840 44.4.0.48/28 via 107.3.166.19 dev tunl0 proto 44 onlink window 840 44.4.2.152/29 via 173.167.109.217 dev tunl0 proto 44 onlink window 840 ..... alot of routes here ..... 44.185.66.0/24 via 89.106.108.151 dev tunl0 proto 44 onlink window 840 44.185.69.0/24 via 80.80.140.38 dev tunl0 proto 44 onlink window 840 44.185.80.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.92.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.96.0/24 via 213.91.190.32 dev tunl0 proto 44 onlink window 840 44.185.103.0/24 via 89.190.200.249 dev tunl0 proto 44 onlink window 840 44.185.104.0/24 via 178.254.198.205 dev tunl0 proto 44 onlink window 840 44.185.105.0/24 via 91.139.210.119 dev tunl0 proto 44 onlink window 840 44.185.106.0/24 via 95.158.166.222 dev tunl0 proto 44 onlink window 840 44.185.107.0/24 via 77.70.122.201 dev tunl0 proto 44 onlink window 840 44.185.108.0/27 via 78.83.56.107 dev tunl0 proto 44 onlink window 840 44.185.109.0/24 via 91.92.93.15 dev tunl0 proto 44 onlink window 840 44.188.1.1 via 70.80.196.6 dev tunl0 proto 44 onlink window 840 44.188.192.222 via 176.67.24.190 dev tunl0 proto 44 onlink window 840 44.224.0.0/15 via 141.75.245.225 dev tunl0 proto 44 onlink window 840
-
Ian Redden -
Ruben ON3RVH