After upgrading Ubuntu from 17.04 to 18.04 zOs came up fine but without any connectivity to external IP destinations.
Nothing was changed other than upgrading Ubuntu so I assume some Linux network configuration setup was modified by the upgrade process.
Linux has 2 Ethernet adapters with IPs: 192.168.1.49 & 192.168.1.48
The z/OS home IP address on this subnet is 192.168.1.249
Main router IP is: 192.168.1.254
The TAP0 subnet is 10.0.0.x and z/os can connect to the Linux host via the tunnel subnet.
From a windows PC on same subnet I can PING 192.168.1.49 & 192.168.1.48 which are the 2 ethernet adapters attached to the Linux macine.
but when I ping the zOs IP at 192.168.1.249 it works sometimes but also tends to fail with following error:
C:\Users\Dani>Ping 192.168.1.249
Pinging 192.168.1.249 with 32 bytes of data:
Reply from 192.168.1.48: TTL expired in transit.
Reply from 192.168.1.48: TTL expired in transit.
Reply from 192.168.1.48: TTL expired in transit.
Reply from 192.168.1.48: TTL expired in transit.
Ping statistics for 192.168.1.249:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
From z/OS I can ping the host Linux at 10.1.1.1 and also 192.168.1.48
but ping to 192.168.1.49 (which is the ethernet adapter z/os is supposed to use for connecting to the outside world) works intermittently.
same goes for ping to other local IPs on the 192.168.1.x subnet. it works for a while but then other times it times out.
I assume it is a configuration issue, and I have a feeling that some network definition in Ubuntu has changed during the release upgrade leading to the problem at hand.
Here are the TCPIP definitions:
;
;This device defines the tunnel to Linux host
;
DEVICE PORTA MPCIPA
LINK ETH1 IPAQENET PORTA
HOME 10.1.1.2 ETH1
;
; This second device is a dedicated Ethernet adapter
;
DEVICE PORTB MPCIPA
LINK ETH2 IPAQENET PORTB
HOME 192.168.1.249 ETH2
;
BEGINRoutes
; Destination SubnetMask FirstHop LinkName Size
ROUTE 192.168.1.0 255.255.255.0 = ETH2 MTU 1492
ROUTE 10.1.1.0 255.255.255.0 = ETH1 MTU 1492
ROUTE DEFAULT 192.168.1.254 ETH2 MTU 1492
ENDRoutes
;
Here is the DEVMAP OSA entries:
[manager] # tap0 define network adapter (OSA) for communication with Linux
name awsosa 0009 --path=A0 --pathtype=OSD --tunnel_intf=y # QDIO mode
device 400 osa osa --unitadd=0
device 401 osa osa --unitadd=1
device 402 osa osa --unitadd=2
[manager] # eth2 define network adapter (OSA) for communication with external networks
name awsosa 1234 --path=F1 --pathtype=OSD --interface=enp5s0
device 404 osa osa
device 405 osa osa
device 406 osa osa
Here is the output from "find_io":
Interface Current MAC IPv4 IPv6
Path Name State Address Address Address
------ ---------------- ---------------- ----------------- ---------------- --------------
F0 enp0s31f6 UP, RUNNING 2c:4d:54:d4:94:d7 192.168.1.48 fe80::98d5:c90a:6bdc:4a25%enp0s31f6
F1 enp5s0 UP, RUNNING 84:16:f9:06:2a:2a 192.168.1.49 fe80::5dda:949d:3553:ac9f%enp5s0 .
A0 tap0 UP, RUNNING 52:f1:fd:86:b1:1c 10.1.1.1 fe80::50f1:fdff:fe86:b11c%tap0
danik1956