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Your TCPIP profile BEGINROUTES statement has the correct IP address for
the use of TUN devices on Linux. The recommendation previously made
works for Windows TUN devices only.
TUN on Linux is a IP forwarding implementation.
TUN on Windows is a Ethernet frame forwarding implementation.
This makes all of the difference in the world.
I strongly suspect your issue with pings to the router from your OS is
that the router does not know how to get the ping back to the PC. To
accomplish this, you need to enable Proxy ARP on your PC's Ethernet
interface. You did not mention this, so, I am assuming you did not do
this.
I also have some concerns that your MTU's are not consistent, but one
thing at a time.
I continue to express that the underlying network implementations are
different between Windows and all of the other host OS's supported by
Hercules. The differences impact the guest OS, the PC, and external
devices. But this seems to go over everyone's head. Rules for Linux
vs. Windows are different.
TAP devices are another story.
Sorry for a bit of ranting.
Harold Grovesteen
On Thu, 2019-06-13 at 19:25 -0400, John Murray [email protected]
[hercules-390] wrote:
>
>
> Hi. I'm currently running z/OS 2.10.00 under Hercules 4.0.0.0 on
> MacOS Mojave (10.14.5). Like many others I'm running into network
> problems. As well like many others I've read this forum and whatever
> information I can find on line, but so far without success. Now
> having said that, networking will occasionally work, but I can't for
> the life of me figure out why. I'll show you what I can, but I'm
> hoping that there's some easy solution that I'm missing or (more
> likely) overlooked.
>
> First, I've got tun/tap installed:
>
> 508> ls /dev/tun*
> /dev/tun0 /dev/tun10 /dev/tun12 /dev/tun14 /dev/tun2 /dev/tun4
> /dev/tun6 /dev/tun8
> /dev/tun1 /dev/tun11 /dev/tun13 /dev/tun15 /dev/tun3 /dev/tun5
> /dev/tun7 /dev/tun9
>
> 509> ls /dev/tap*
> /dev/tap0 /dev/tap10 /dev/tap12 /dev/tap14 /dev/tap2 /dev/tap4
> /dev/tap6 /dev/tap8
> /dev/tap1 /dev/tap11 /dev/tap13 /dev/tap15 /dev/tap3 /dev/tap5
> /dev/tap7 /dev/tap9
>
> And using ifconfig (with Hercules running):
>
> utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000
> inet6 fe80::d1b2:4144:8e63:d419%utun0 prefixlen 64 scopeid 0xc
> nd6 options=201<PERFORMNUD,DAD>
> utun1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
> inet6 fe80::8052:25e9:e02b:1178%utun1 prefixlen 64 scopeid 0xd
> nd6 options=201<PERFORMNUD,DAD>
> utun2: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
> inet6 fe80::59fd:1d39:c29c:9aa6%utun2 prefixlen 64 scopeid 0xe
> nd6 options=201<PERFORMNUD,DAD>
> tun0: flags=8851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST> mtu 1500
> inet 192.168.2.27 --> 192.168.2.210 netmask 0xffffff00
> open (pid 12790)
>
> Before starting Hercules I start IP forwarding:
>
> sudo sysctl -w net.inet.ip.forwarding=1
>
> And in hercules.cnf I have:
>
> 0E20.2 3088 CTCI --dev /dev/tun0 -s 255.255.255.255 -t 1500
> 192.168.2.210 192.168.2.27
>
> Note that my router's IP address is 192.168.2.1.
>
> Once I start Hercules:
>
> sudo hercules -f hercules.cnf
>
> and IPL z/OS, I wait for system initialization to complete and then I
> stop tcpip and add the following to tcpip.profile.tcpip:
>
> DEVICE CTCDEVICE CTC E20
> LINK CTCLINK CTC 1 CTCDEVICE
> HOME 192.168.2.210 CTCLINK
>
> BEGINROUTES
> ROUTE 192.168.2.1 255.255.255.0 = CTCLINK MTU DEFAULTSIZE
> ROUTE DEFAULT 192.168.2.27 CTCLINK MTU DEFAULTSIZE
> ENDROUTES
>
> START CTCDEVICE
>
> Note that I only need to make this change once.
>
> Then I restart tcpip. Note that I also verify that CTCDEVICE starts.
>
> After all that I try pinging zOS:
>
> 512> ping 192.168.2.210
> PING 192.168.2.210 (192.168.2.210): 56 data bytes
> Request timeout for icmp_seq 0
> Request timeout for icmp_seq 1
> Request timeout for icmp_seq 2
> Request timeout for icmp_seq 3
> Request timeout for icmp_seq 4
> etc
>
> Similarly telnet and ftp fail.
>
> So what's going on? How can I get this to work reliably?
>
> As always, thanks for your help.
>
>
>
> --
> John Murray
>
>