Re: Hercules networking redux

Thanks for that. Yes, I made the TCPIP profile changes suggested earlier and indeed, they didn’t work. Now the thing of all this is, I’m running Hercules on a Mac (hence MACOS) which, under the covers, is Unix. But most of the responses I’ve received for this problem are set in a Linux context and, as we all know, Linux is not Unix, so the question I have is really, what should I be doing for MACOS?

Thanks as always.


John Murray

Ottawa

> On 14 Jun 2019, at 10:40, Harold Grovesteen [email protected] [hercules-390] <[email protected]> wrote:
> 
> 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] <mailto:[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
> > 
> > 
> 
>