IBM SC30-3865-04 126

Table17. Conﬁguration Parameter List - Port Conﬁguration (continued)

Parameter Information

Parameter

Port name

ValidValues

Astring of 1 to 8 characters, where the ﬁrst character is alphabetic and the 2nd through

8th characters are alphanumeric.

Default Value

Aunique unqualiﬁed name that is automatically generated.

The name will consist of:

vTR (token-ring)

vEN (Ethernet)

vDLS (DLSw)

vIP255

vATM

vFR (frame relay)

vX25 (X.25)

vSDLC (SDLC)

vPPP (point-to-point)

vIP

followed by the interface number.

Youcan change the port name to a name of your choice.

Description

This parameter speciﬁes the name representing this port.

Parameter

EnableAPPN routing on this port

ValidValues

Yes,No

Default Value

Yes

Description

This parameter speciﬁes whetherAPPN routing is to be enabled on this port.

Parameter

Support multiple PU

ValidValues

Yes,No

Default Value

Description

This parameter speciﬁes whether the port will support multiple subarea.

APPN Conﬁguration Commands

126 MRS V3.2 Protocol Conﬁg Ref Vol2

Contents

Main Page Page Page Contents iv Page vi Page viii Page x Figures Page Tables xiv Notices Page Notice to Users of Online Versions of This Book Page Trademarks Page About the Software Conguration Program Conguration Program Users Guide for Nways Multiprotocol and Access Services Products, Conventions Used in This Manual IBM 2210 Nways Multiprotocol Router Publications xxii xxiii IBM 2210 Nways Multiprotocol Router Installation and Initial Conguration Guide IBM 2210 Nways Multiprotocol Router Service and Maintenance Manual Summary of Changes for the IBM 2210 Software Library xxiv dont fragment xxv Editorial Changes Using and Conguring Features Software Users Guide Getting Help xxvi Exiting a Lower Level Environment xxvii Page Chapter 1. APPN What is APPN? peer relationship Peer-to-Peer Communications APPN Node Types APPN End Nodes 2 LEN Nodes PU 2.0 Nodes What APPN Functions Are Implemented on the Router? Table1. Implementation of APPN Network Node Functions (continued) 4 caches APPN Network Node Optional Features High-Performance Routing 6 Interoperability Traffic types 8 Dependent LU Requester (DLUR) Functions Supported Restrictions VTAM Considerations for DLUR 10 VTAM Resource Denition Reference Page APPN Connection Network 12 Restrictions connection network name Branch Extender Extended Border Nodes 14 Network Topology Example Session Services Extensions (SSE) for NNS Support Network Requirements 16 Branch Extender vs. Extended Border Node Managing a Network Node Entry Point Capabilities for APPN-related Alerts explicit focal point focal point sphere of control Supported Message Units 18 SNMP Capabilities for APPN MIBs Topology Database Garbage Collection Congurable Held Alert Queue Implicit Focal Point Dynamic Denition of Dependent LUs (DDDLU) TN3270E Server 20 TN3270 LU Pooling Multiple TN3270E Ports TN3270E Server Client IP Address to LU Name Mapping 22 How LUs are Chosen For Client Connections <DEFLT> Support for Subarea SNA Connections from the TN3270E Server to the Host 24 Enterprise Extender Support for HPR over IP Supported DLCs Router Conguration Process Conguration Changes That Require the APPN Function to Restart Conguration Requirements for APPN Conguring the Router as an APPN Network Node 26 Minimum Conguration Service Any Initiate Connections Conguration enable APPN routing on this port 28 Service Any Controlling Connections Conguration APPN routing service any port Service any Conguring Branch Extender Branch uplink 30 Branch uplink Permit search for unregistered LUs Conguring Extended Border Nodes Set node limited List optimization Add port 32 Adjacent subnetwork affiliation Add link adjacent subnetwork affiliation Add Routing List(s) routing list name list optimization Add COS Mapping Table 34 COS mapping table name Non-native CP default COS mapping COS name pairs default COS mapping table High-Performance Routing DLUR 36 Held Alert Queue Size Conguring Focal Points Calculating APPN Routes Using TG Characteristics COS Options SNA APPN Architecture Reference 38 APPN Node Tuning Tuning Notes Node Service (Traces) APPN Trace Enhancements Turn all trace ags off save RSCV information for intermediate sessions Accounting and Node Statistics 40 DLUR Retry Algorithm Perform long retries to restore disrupted pipe Long retry timer Perform retries to restore disrupted pipe Delay before initiating retries 42 Short retry timer Short retry count Long retry timer Short retry count APPN Implementation on the Router Using DLSw How APPN Uses DLSw ports to Transport Data APPN Frame Relay BAN Connection Network Implementation 44 Sample APPN Frame Relay BAN Connection Network Denitions 46 Page Port Level Parameter Lists Link Level Parameter Lists 48 LU Parameter List Node Level Parameter Lists APPN Conguration Notes Conguring a Permanent Circuit Using ISDN 50 Conguring APPN Over Dial on Demand Circuits PU 2.1 Node Considerations PU 2.0 Node Considerations Considerations When Using DLUR for T2.0 or T2.1 Devices activate link automatically 52 Page Conguring WAN Reroute 54 Page 56 Page 1The primary route is interface 1, frame relay 58 Conguring WAN Restoral Conguring V.25bis 60 Page Conguring V.34 The following is a sample V.34conguration that could be used when APPN traffic uses PPP over V.34: 62 Conguring APPN Over ATM The following sample congures APPN overATM. 64 Conguring APPN Using SDLC 66 Page 68 Page Conguring APPN Over X.25 70 Page 72 Conguring APPN Over Frame Relay The following example shows conguration of APPN over Frame Relay. Conguring APPN Over Frame Relay BAN The following example shows conguration of APPN over Frame Relay BAN. 74 Conguring TN3270E Using DLUR 76 Conguring TN3270E Using a Subarea Connection 78 Conguring Enterprise Extender Support for HPR Over IP Conguring Connection Networks over HPR over IP Conguring an Extended Border Node 80 Chapter 2. Conguring and Monitoring APPN Accessing the APPN Conguration Process conguration APPN Conguration Command Summary Note: APPN will respond to a dynamic reset command at the interface level. APPN Conguration Commands (Talk6) 82 APPN Conguration Command Detail Enable/Disable port name 84 branch extender with the same NETID 86 Page 88 set high-performance routing Table5. Conguration Parameter List - High-Performance Routing (HPR) Table6. Conguration Parameter List - HPR Timer and Retry Options Low transmission priority traffic low 90 Medium transmission priority traffic medium High transmission priority traffic high Network transmission priority traffic 92 network set dlur Table7. Conguration Parameter List - Dependent LU Requester 94 short retry timer Perform retries to restore disrupted pipes Delay before initiating retries Perform retries to restore disrupted pipes 96 set tuning Note: Youwill have to re-boot in order for the changes you specify to take place. Table8. Conguration Parameter List - APPN Node Tuning Maximum number of ISR sessions maximum number of network nodes in the subnetwork Maximum cached directory entries Maximum shared memory 98 Page 100 percent of APPN shared memory used for buffers maximum shared memory percent of APPN shared memory used for buffers set traces Table9. Conguration Parameter List - Trace Setup Questions 102 Table9. Conguration Parameter List - Trace Setup Questions (continued) Table10. Conguration Parameter List - Node Level Traces 104 Page 106 Page Table11. Conguration Parameter List - Inter-process Signals Traces 108 Page 110 Page Table12. Conguration Parameter List - Module Entry and Exit Traces 112 Page Table12. Conguration Parameter List - Module Entry and Exit Traces (continued) 114 Table13. Conguration Parameter List - General Component Level Traces Page 116 Page 118 Table14. Conguration Parameter List - Miscellaneous Traces length to trace Table14. Conguration Parameter List - Miscellaneous Traces (continued) 120 Table14. Conguration Parameter List - Miscellaneous Traces (continued) set management Table15. Conguration Parameter List - APPN Node Management Table15. Conguration Parameter List - APPN Node Management (continued) 122 collect intermediate session information Table15. Conguration Parameter List - APPN Node Management (continued) Table16. Conguration Parameter List - APPN ISR Recording Media Memory Parameters Table16. Conguration Parameter List - APPN ISR Recording Media (continued) 124 Use the add command to add or update: add port Table17. Conguration Parameter List - Port Conguration 126 Page dial on demand 128 2 Table18. Conguration Parameter List - Port Conguration for ATM 130 Page 132 Page Page Table19. Conguration Parameter List - Port Denition 136 Page 138 Page Table20. Conguration Parameter List - Port Default TG Characteristics 140 Page 142 Page 144 Page Table21. Conguration Parameter List - Port default LLC Characteristics 146 Page Table21. Conguration Parameter List - Port default LLC Characteristics (continued) 148 Table22. Conguration Parameter List - HPR Override Defaults Table22. Conguration Parameter List - HPR Override Defaults (continued) add link-station no Table23. Conguration Parameter List - Link Station - Detail 150 X'xyxxxxxxxxxx' x y APPN end node 152 learn LEN end node APPN end node LEN end node Service any node Adjacent node type CP-CP session level security 154 Page link type 156 SVC yes, link type 158 2 Table24. Conguration Parameter List - Station Conguration for ATM 160 Page 162 Page 164 Table25. Conguration Parameter List - Modify TG Characteristics Table25. Conguration Parameter List - Modify TG Characteristics (continued) 166 Table25. Conguration Parameter List - Modify TG Characteristics (continued) Table26. Conguration Parameter List - Modify Dependent LU Server 168 Table27. Conguration Parameter List - Modify LLC Characteristics Table27. Conguration Parameter List - Modify LLC Characteristics (continued) 170 Table27. Conguration Parameter List - Modify LLC Characteristics (continued) Table28. Conguration Parameter List - Modify HPR Defaults Table28. Conguration Parameter List - Modify HPR Defaults (continued) 172 Table29. Conguration Parameter List - LEN End Node LU Name netID.LUname LUname add connection-network Table30. Conguration Parameter List - Connection Network - Detail 174 NetworkID NetworkID.ConnectionNetworkName Page Table30. Conguration Parameter List - Connection Network - Detail (continued) 176 Table31. Conguration Parameter List - Connection Network Conguration for ATM CNname netID.CNname Page 178 Page Table32. Conguration Parameter List - TG Characteristics (Connection Network) 180 Page 182 add mode Table33. Conguration Parameter List - APPN COS - Mode Name to COS Name Mapping - Detail Table33. Conguration Parameter List - APPN COS - Mode Name to COS Name Mapping - Detail (continued) 184 add additional-port-to-connection-network Note: Youcan have a maximum of 5 ports per connection network denition. Table34. Conguration Parameter List - APPN Additional port to Connection Network NetworkID add focal_point Table35. Conguration Parameter List - APPN Implicit Focal Point 186 add local-pu Table36. Conguration Parameter List - APPN Local PU Page 188 Table37. Conguration Parameter List - Routing List Conguration Page Table37. Conguration Parameter List - Routing List Conguration (continued) 190 Table38. Conguration Parameter List - COS Mapping Table Conguration Table38. Conguration Parameter List - COS Mapping Table Conguration (continued) 192 Use the delete command to delete: Activate_new_cong TN3270E Table39. TN3270E Conguration Command Summary Table40. Conguration Parameter List - Set TN3270E 194 Page Timing mark NOP 196 Table41. Conguration Parameter List - Add TN3270E Implicit 198 Page Table42. Conguration Parameter List - Add TN3270E LU 200 Page Table42. Conguration Parameter List - Add TN3270E LU (continued) class add map 202 Page Table43. Conguration Parameter List - Add TN3270E Map (continued) Table44. Conguration Parameter List - Add TN3270E Port 204 Table44. Conguration Parameter List - Add TN3270E Port (continued) Table45. Conguration Parameter List - Delete TN3270E LU delete implicit-pool Table46. Conguration Parameter List - Delete TN3270E Implicit 206 Table47. Conguration Parameter List - Delete TN3270E Map Monitoring APPN Accessing the APPN Monitoring Commands monitoring 208 APPN Monitoring Commands Aping ags lu_name Save RSCV information for intermediate sessions 210 port name station name Memory Restart Stop TN3270E poolname 212 Chapter 3. Using AppleTalk Phase 2 Basic Conguration Procedures interface number Enabling Router Parameters Setting Network Parameters AppleTalk over PPP AppleTalk 2 Zone Filters 214 General Information Why ZoneName Filters? How Do You Add Filters? Other Commands: Sample Conguration Procedures 216 Enabling AP2 Setting Network Parameters Setting Up Zone Filters Setting Up Network Filters 218 Page Page Chapter 4. Conguring and Monitoring AppleTalk Phase 2 Accessing the AppleTalk Phase 2 Conguration Environment AppleTalk Phase 2 Conguration Commands 222 Page 224 Page exclusive 226 exclusive interface# enabled exclusive exclusive interface# Page value Cache-size 228 interface# rst# last# only rst# interface# node# Accessing the AppleTalk Phase 2 Monitoring Environment AppleTalk Phase 2 Monitoring Commands Atecho dest_net dest_node AppleTalkPhase 2 Monitoring Commands (Talk 5) 230 Clear Counters AppleTalk Phase 2 Monitoring Commands (Talk5) Interface AppleTalkPhase 2 Monitoring Commands (Talk 5) 232 Chapter 5. Using VINES VINES Protocol Denition, VINES Overview VINES Over Router Protocols and Interfaces Service and Client Nodes VINES Network Layer Protocols VINES Internet Protocol (VINES IP) 234 VINES IP Implementation Routing Update Protocol (RTP) Routing Table 236 Neighbor Tables RTP Implementation RTP request packets. RTP update packets. RTP response packets. Internet Control Protocol (ICP) VINES Address Resolution Protocol (VINES ARP) 238 Basic Conguration Procedures hex # Running Banyan VINES on the Bridging Router Running Banyan VINES over WAN Links Chapter 6. Conguring and Monitoring VINES Accessing the VINES Conguration Environment remote-X.25-addr VINES Conguration Commands VINES Conguration Commands (Talk6) 242 VINES Conguration Commands (Talk 6) hex# Hex# # VINES Conguration Commands (Talk6) 244 Accessing the VINES Monitoring Environment VINES Monitoring Commands VINES Conguration Commands (Talk 6) VINES Monitoring Commands (Talk5) 246 VINES Monitoring Commands (Talk 5) VINES Monitoring Commands (Talk5) 248 Chapter 7. Using DNA IV DNA IV Overview DNA IV Terminology and Concepts Addressing 250 Ethernet Data Link Addressing 802.5 Token-Ring Data Link Addressing Routing Routing Tables Area Routers Conguring Routing Parameters 252 IBMs Implementation of DNA IV Managing Traffic Using Access Control Conguring Access Control Inclusive Access Control 254 Exclusive Access Control Managing Traffic Using Area Routing Filters DECnet Digital Network Architecture Phase-IV Routing Layer Functional Description 256 Security by Area Filtering Blending DECnet Domains 258 Page 260 Conguring DNA IV DNA IV and DNA V Algorithm Considerations Conguring DNA IV For Token Ring Conguring DNA IV for X.25 262 Page 264 Chapter 8. Conguring and Monitoring DNA IV DNA IV Conguration and Monitoring Commands All not Dene/Set arguments 266 Page Standard 268 AMA DEC-area DEC-routing-IV Bilingual Page 270 off circuit-specier argument 272 circuit-specier argument Purge Show 274 Page 276 Show/List 278 Page 280 Page 282 Zero Page Chapter 9. Using OSI/DECnet V OSI Overview NSAP Addressing IDP 286 DSP IS-IS Addressing Format Area Address System ID Selector GOSIP Version 2 NSAPs Multicast Addresses 288 OSI Routing IS-IS Protocol IS-IS Areas IS-IS Domain Synonymous Areas Figure 24. OSI Domain IS to IS Hello (IIH) Message L1 IIH Message 292 L2 IIH Message Point-to-Point IIH Message Designated IS Link State Databases Link State Flooding 294 L1 Link State Update (non-pseudonode) L1 Link State Update (pseudonode) Routing Tables L1 Routing L2 Routing Routing Metric 296 Internal and External Routing Address Prex Encoding Encoding a Fixed Length IDI Encoding an AFI Encoding a Variable Length IDI 298 Authentication Passwords ESIS Protocol Hello Message End System Hello (ESH) Message Intermediate System Hello (ISH) Messages X.25 Circuits for DECnet V/OSI Routing Circuits lters 300 lter templates Templates Link Initialization OSI/DECnet V Conguration Basic Conguration Procedure Conguring OSI Over an Ethernet or a Token-Ring LAN Conguring OSI Over X.25 or Frame Relay 302 Conguring a DNA V Router for a DNA IV Environment DNA IV and DNA V Algorithm Considerations Page Chapter 10. Conguring and Monitoring OSI/DECnet V Accessing the OSI Conguration Environment DECnet V/OSI Conguration Commands a-z, A-Z, 0-9 306 newname area-addr lter-name routing-circuit-name calling-DTE call-UserData priority calling-DTE priority call-UserData user dec 308 Page 310 Page 312 manual X.121 routingcircuitname template-name Clear Domain 314 Area only Page intfc# 316 Intfc# template-name Page 318 Page 320 subnet.reprt intfc# Subnet.reprt Intfc# Detailed Summary 322 Page 324 Page 326 Page 328 domain area. Getting Started (Introduction to the User Interface) Accessing the OSI/DECnet V Monitoring Environment OSI/DECnet V Monitoring Commands The monitoring commands either display or modify the volatile database. Table61. OSI/DECnet V Monitoring Commands Summary Addresses Use the addresses command to list the routers NET and the area addresses congured for this router. 330 addresses Network Entity Title Identies the router. The NETconsists of an area address and a system ID. Change Metric CLNP-Stats 332 Designated-router DNAV-info ES-Adjacencies ES-IS-Stats 334 Page IS-Adjacencies IS-IS-Stats 336 Page L1-Routes L2-Routes 338 L1-Summary L2-Summary L1-Update 340 L2-Update Ping-1139 dest-nsap Send (Echo Packet) 342 Subnets Toggle (Alias/No Alias) Traceroute 344 Chapter 11. Using NHRP Next Hop Resolution Protocol (NHRP) Overview Benets of NHRP and the IBM implementation 346 Performance Characteristics Examples of NHRP Congurations NHRP in an RFC 1577 Classic IP Environment with All Devices NHRP-capable NHRP in a Classic IP Environment with non-NHRP Device NHRP in a Pure LAN Emulation Environment NHRP in a LAN Emulation Environment with LAN Switches NHRP in a Mixed Classical IP and ELAN Environment NHRP to an Egress Router NHRP Implementation Virtual Network Interface (VNI) 352 LANE Shortcut Interface (LSI) Conguration Parameters NHRP Auto-Conguration Exclude Lists 354 Destination Devices: Next-hop Routers: Extensions Path Information Extensions: IBM Vendor-Private Extensions: Disallowed Router-to-Router Shortcuts address=9.9.9.1 mask=255.255.255.255 Protocol Access Control Usage 356 source and destination NHRP Access Controls ATM Network ID Conguring the LANE Shortcuts Interface (LSI) Conguring Devices in an ATM Network Using NHRP with LAN Emulation 358 Chapter 12. Conguring and Monitoring NHRP Accessing the NHRP Conguration Process NHRP Conguration Commands Enable NHRP Disable NHRP Advanced Cong 360 NHRP Conguration Commands (Talk6) NHRP Advanced Conguration Commands NHRP Conguration Commands (Talk 6) 362 Page 364 Page 366 no registration resolution server purge Accessing the NHRP Monitoring Process 368 NHRP Monitoring Commands Box Status Interface Status Statistics 370 Server_purge_cache MIB LANE Shortcuts 372 CONFIG Parameters Display Change Reset Reset NHRP Packet Tracing 374 Software Users Guide Sample trace output #2: NHRP Packet Tracing Page Chapter 13. Using IP Version 6 (IPv6) IPv6 Overview IPv6 Comparison with IPv4 IPv6 Addressing IPv6 Address Format Text Representation of Address Prexes 378 IPv6 Header Format IPv6 Minimum MTU IPv6 Mandatory Path MTU Discovery IPv6 Mandatory Security Using and Conguring Features IPv6 Neighbor Discovery Protocol (NDP) Router and Prex Discovery Address Autoconguration Address Resolution Neighbor Unreachability Detection Redirect IPv6 over IPv4 Tunneling Protocol Independent Multicast (PIM) 382 Chapter 14. Conguring and Monitoring IPV6 Accessing the IPV6 Conguration Environment IPV6 Conguration Commands add address net address prex 384 Page 386 net address prex name interface destination mask gateway cost ... destination prex raddress locaddress cost ttl fragmentation destination mask gateway 388 Page 390 Use the set command to set conguration parameters. set access-control automatic-tunnel-parameters default cache-size ttl fragmentation hopcount #entries internal-ip-address mld path-mtu-aging-timer reassembly-size router-id routing #nets 392 Page Update Update Packet-lter Commands 394 Add type sourceaddr sourceprex destaddr destprex Change type sourceaddr sourceprex destaddr destprex Delete index# Move index# after# 396 Accessing the IPV6 Monitoring Environment Software Users Guide IPV6 Monitoring Commands This section describes the IPV6 monitoring commands. Table68. IPv6 Monitoring Command Summary Use the cache command to display cache Dump routing tables Use the dump command to display the congured routing tables. dump Interface addresses Use the interface command to display addresses congured on the interface. Mld Use the mld command to display congured. mld counters parameters Use the route command to show the route to the IPv6 address. route Static routes Packet-lter Path-mtu Ping6 Traceroute6 402 Tunnels Page Chapter 15. Conguring and Monitoring Neighbor Discovery Protocol (NDP) Accessing the NDP Conguration Environment NDP Conguration Commands 406 NDP Conguration Commands (Talk 6) no 408 Accessing the NDP Monitoring Environment NDP Conguration Commands (Talk 6) NDP Monitoring Commands This section describes the NDP monitoring commands. Table70. NDP Monitoring Command Summary See Dump routing tables on page416 for information about the dump command. Ping6 Chapter 16. Conguring and Monitoring Protocol Independent Multicast Routing Protocol (PIM) Accessing the PIM Conguration Environment PIM Conguration Commands interfaceaddr PIM Conguration Commands (Talk6) 412 interfaceaddress helloperiod joinpruneholdtime routetype preferencevalue PIM Conguration Commands (Talk 6) PIM Conguration Commands (Talk6) 414 Accessing the PIM Monitoring Environment PIM Conguration Commands (Talk 6) PIM Monitoring Commands This section describes the PIM monitoring commands. Table72. PIM Monitoring Command Summary Dump routing tables Use the dump command to display the congured routing tables. Interface Join Leave Mcache Mgroup 418 internal Mstats Neighbor 420 PIM Summary PIM Ping Traceroute 422 Variables Page Chapter 17. Conguring and Monitoring Routing Information Protocol (RIP6) Accessing the RIP6 Conguration Environment RIP6 Conguration Commands 426 Page 428 Page 430 Accessing the RIP6 Monitoring Environment RIP6 Monitoring Commands Page Appendix A. Comparison of Protocols Protocol Comparison Table The following table compares the protocols. Table75. Comparison Protocols Key to Protocols Page Appendix B. Packet Sizes General Issues Network-Specic Size Limits Protocol-Specic Size Limits IP Packet Lengths 436 Changing Maximum Packet Sizes Packet Sizes List of Abbreviations 438 Page 440 Page 442 Page 444 Page Page Glossary American National Standard Dictionary for Information Systems IBM Dictionary of Computing Fiber Optic Terminology Information TechnologyVocabulary 448 subnetwork mask digital broadcast address AppleTalkAddress Resolution Protocol (AARP) B multicast all-stations address C line switching 450 data service unit (DSU) noncanonical address D received line signal detector (RLSD) connection virtual level 452 physical level DCE ready spoong encapsulation segment data set ready (DSR) name server domain name Administrative Domain E no response 454 explorer packet denite response G H I Internet 456 RouTing update Protocol (RTP) IP address L circuit switching 458 token ring universally administered address remote bridging wide area network (WAN) M wide area network (WAN) MIB object MIB variable modulus N 460 Networking (APPN) network node destination virtual route (VR) pacing O P packet mode operation 462 circuit switching socket subarea PU peripheral PU R data carrier detect (DCD) explicit route (ER) path nonseed router S 464 destination service access point (DSAP) Internet Control Protocol (ICP) 466 address mask subnet RouTing update Protocol (RTP) subnetwork T multilink transmission group (MLTG) locally administered address physical circuit mixed-media multilink transmission group (MMMLTG) U V 468 data StreetTalk W pattern-matching character X Internetwork Packet Exchange (IPX) Z Page Index A B C D 472 E F H I J L 474 M N O P R 476 S T U V W Page Readers Comments Wed Like to Hear from You Readers Comments Wed Like to Hear from You IBMR ___________________________________________________________________________________________________ SC30-3865-04 BUSINESS REPLY MAIL