Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1: Base Functions, Connectivity, and Routing

130 Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1 - Base Functions, Connectivity, and Routing

Modifying characteristics of a device

You can temporally modify the characteristics of a device by issuing the OBEY command:

Vary TCPIP,tcpipproc,OBEYFILE,datasetname

Authorization to use this command is through the user’s RACF profile. The datasetname

cannot be a z/OS UNIX file system file. The data set contains the modified TCP/IP

configuration statements (see Example 4-15).

Example 4-15 OBEYFILE example

;Original BSDROUTINGPARMS statement for link OSA20C0

;BSDROUTINGPARMS TRUE

; Link name MTU Cost metric Subnet Mask Dest address

;OSA20C0LNK 1492 0 255.255.255.0 0

;ENDBSDROUTINGPARMS

;Modified BSDROUTINGPARMS statement for link OSA20C0

BSDROUTINGPARMS TRUE

; Link name MTU Cost metric Subnet Mask Dest address

OSA20C0LNK 1024 0 255.255.255.0 0

ENDBSDROUTINGPARMS

4.4.5 Verifying the connectivity status

In this section, we verify the status of all devices defined to the TCP/IP stack or VTAM.

Verifying the device status in TCP/IP stack

To verify the status of all devices being activated in the TCP/IP stack we use the NETSTAT

command with the DEVLIST option, as seen in Example 4-16.

Example 4-16 Using command D TCPIP,TCPIPA,N,DEV to verify the Device status

D TCPIP,TCPIPA,N,DEV

EZD0101I NETSTAT CS V1R7 TCPIPA 810

DEVNAME: OSA2080 DEVTYPE: MPCIPA

DEVSTATUS: READY

LNKNAME: OSA2080LNK LNKTYPE: IPAQENET LNKSTATUS: READY

NETNUM: N/A QUESIZE: N/A SPEED: 0000000100

IPBROADCASTCAPABILITY: NO

CFGROUTER: NON ACTROUTER: NON

ARPOFFLOAD: YES ARPOFFLOADINFO: YES

ACTMTU: 1492

VLANID: 10 VLANPRIORITY: DISABLED

DYNVLANREGCFG: NO DYNVLANREGCAP: YES

READSTORAGE: GLOBAL (4096K) INBPERF: BALANCED

Note: When an OSA-Express device is stopped or loses its connection to the switch,

another OSA-Express device defined to the TCP/IP stack will take over the IP address. A

gratuitous ARP is broadcasted on the LAN to advertise the new MAC address related to

the IP address being taken over. Message EZZ4329I in Example 4-14 indicates this action.

Important: Dynamic XCF cannot be changed by using the OBEYFILE command. If you

want to change the IPCONFIG DYNAMICXCF parameters, stop TCP/IP, code a new

IPCONFIG DYNAMICXCF statement in the initial profile, and restart TCP/IP.

Chapter 4. Connectivity 131

CHECKSUMOFFLOAD: YES SEGMENTATIONOFFLOAD: YES

SECCLASS: 255

BSD ROUTING PARAMETERS:

MTU SIZE: 1492 METRIC: 10

DESTADDR: 0.0.0.0 SUBNETMASK: 255.255.255.0

MULTICAST SPECIFIC:

MULTICAST CAPABILITY: YES

GROUP REFCNT

----- ------

224.0.0.1 0000000001

LINK STATISTICS:

BYTESIN = 506807

INBOUND PACKETS = 2803

INBOUND PACKETS IN ERROR = 5258

INBOUND PACKETS DISCARDED = 0

INBOUND PACKETS WITH NO PROTOCOL = 0

BYTESOUT = 429

OUTBOUND PACKETS = 3

OUTBOUND PACKETS IN ERROR = 0

OUTBOUND PACKETS DISCARDED = 0

Displaying TCP/IP device resources in VTAM

The device drivers for TCP/IP are provided by VTAM. When CS for z/OS IP devices are

activated, there must be an equivalent Transport Resource List Element (TRLE) defined to

VTAM. The devices that are exclusively used by z/OS Communications Server IP have

TRLEs that are automatically generated for them.

Since the device driver resources are provided by VTAM, you have the ability to display the

resources using VTAM display commands.

For dynamically generated TRLEs, the device type and address can be decoded from the

generated TRLE name. The format is IUTtaaaa:

򐂰 IUT - Fixed for all dynamically generated TRLEs.

򐂰 t - Shows the device type, which indicates the following:

– C - Indicates this is a CDLC device.

– H - Indicates this is a HYPERCHANNEL device.

– I - Indicates this a QDIO device.

– L - Indicates this is a LCS device.

– S - Indicates this is a SAMEHOST device.

– W - Indicates this is a CLAW device.

– X - Indicates this is a CTC device.

򐂰 aaaa - The read device number. For SAMEHOST connections, this is a sequence

number.

For XCF links, the format of the TRLE name is ISTTxxyy. ISTT is fixed, xx is the SYSCLONE

value of the originating VTAM, and yy is the SYSCLONE value of the destination VTAM.

To display a list of all TRLEs active in VTAM, use the command D NET,TRL, as shown in

Example 4-17.

Example 4-17 D NET,TRL command output

D NET,TRL

IST097I DISPLAY ACCEPTED

IST350I DISPLAY TYPE = TRL 137

IST924I -------------------------------------------------------------