1. Understanding SLP v2 Novell BrainShare 2002 Heath Ramsey
Novell Consulting
Novell, Inc.
Paul McKeith
TUT 305—Understanding SLP Version 2

2. Agenda IP-based service resolution SLP Theory (RFC 2165/2608)
Novell implementation of SLP
Troubleshooting SLP infrastructures
SLP infrastructure design/best practices

3. Vision…one Net Mission
A world where networks of all types—corporate and public, intranets, extranets, and the Internet—work together as one Net and securely connect employees, customers, suppliers, and partners across organizational boundaries
Mission
To solve complex business and technical challenges with Net business solutions that enable people, processes, and systems to work together and our customers to profit from the opportunities of a networked world

5. Service Resolution IPX RIP/SAP for service resolution
Broadcast based protocols
TCP/IP
Does not lend itself well to broadcast protocols
IPX-like services on the Internet would bring the Net to its knees

6. Service Resolution
Novell supports many different IP-based service resolution mechanisms
Explicit TCP/IP addressing
NWHOSTS file
DNS
NDS (via NCP/IP)
SLP

7. Service Resolution
A single method of service resolution is often not enough
Think about how service resolution mechanisms compliment each other
Leverage the service resolution mechanism that best fits a given environment

8. SLP Theory: Misconceptions
SLP is mandatory in NetWare® 5 and 6
Optional
Only required if
Using compatibility mode
Browsing
Short name resolution
Because SLP is the “replacement for SAP” it will flood the network like SAP
If SLP is implemented on the network, multicast is required
When using SLP and CMD, SLP will become bogged down with SAP information

9. SLP Theory: Comparison to SAP
SLP is not mandatory—SAP is mandatory
SLP is passive—SAP is active
SLP is a pull technology—SAP is a push technology
SLP queries can be tailored to provide useful information—SAP places all information on the wire

10. SLP Theory: User Agent (UA)
Required component of SLP infrastructure
Consumer of SLP information
“Client” piece of SLP
Both NetWare servers and Novell clients have user agents included

11. SLP Theory: Service Agent (SA)
Required component of SLP infrastructure
Provider of SLP information
“Server” piece of SLP
Both NetWare servers and Novell clients have service agents included

12. SLP Theory: Directory Agent (DA)
Optional component of SLP infrastructure
Provides central repository of service information on the network
NetWare servers currently come with directory agents
NetWare 5.x – SLP v1
NetWare 6.x – SLP v2
Novell eDirectory™ 8.5 for NT/W2k includes a v1 directory agent

13. Default SLP Communications
“Out of the box” SLP infrastructure
Only UA and SA present on network
Involves the use of multicast for service resolution
Does not scale well

14. Default SLP Communications
User Agent
requests services
Service Agent
has service; reply is
unicast
does not have
service;
no reply
Multicast SLP packet
addressed to
Unicast SLP packet
addressed to original host

15. SLP Communications with DA
DA is central repository of SLP information
DA(s) must be discovered by UA and SA on network
Once discovered, all UA/SA/DA communication is direct unicast packets

16. SLP Communications with DA
Unicast SLP packet
addressed to original host
DA1
Directory Agent
responds
DA List
DA1
DA2
DA3
Unicast SLP packet
addressed to original host
Multicast SLP packet
User or Service
addressed to
DA2
Agent
Directory Agent
Looks for Directory
responds
Agent
Unicast SLP packet
addressed to original host
DA3
Directory Agent
responds

17. SLP Bottlenecks Bandwidth on the wire DA hardware configuration
Multicast can adversely affect the performance of the network
UA issues a multicast and every SA will respond with a packet
Avoided through the use of the DA
DA hardware configuration
DA local cache can grow large
Cache cannot be searched in enough time and the SLP service request times out
Fixed by using scopes
Limits the amount of information stored on the DA

18. Scoping Generally used for two reasons
Scalability
Filtering
Allows administrators to control which network services are browsed

19. Scoping Services Learned Services Learned SA1 Service Registration
Service Request
Acknowledgement
Service Agent
DA1 servicing
User Agent belonging
belonging
Scope 1
to Scope 2 and
to Scope 1
configured
with address of DA1

20. Scoping Precautions Do not use the UNSCOPED option
In SLP v1 the options were for scoped or UNSCOPED
SLP v2 does not support the UNSCOPED option
A custom scope should be implemented in preparation for SLP v2 (NetWare 6)

21. SLP Overview: Question and Answer
You have questions…I have answers…

22. Novell Implementation of SLP
Software versions with SLP v1 capabilities
NetWare 4.x (w/ latest service pack)
NetWare 5.x
Windows 95/98 version 2.5 and later
Recommend latest version of client
Windows NT version 4.11b and later
Software versions with SLP v2 capabilities
NetWare 6

23. The DA Problem Service List SA1 SA2 Directory Agent creates
entry for services
registered
Service registration using
unicast SLP packet
Service registration using
unicast SLP packet
DA1
Unicast SLP
request for
list of services
ACK
ACK
Unicast SLP response
DA List
Services Learned
DA List
DA1
SA1
DA1
DA2
SA2
Service Agent 1
Service Agent 2
User Agent
ACK
Service registration using
unicast SLP packet
DA2
Directory Agent creates
Service List
entry for services
SA1
registered

24. The DA Solution eDirectory
Partitionable
Replicatable
Synchronizes
With the NetWare DA, eDirectory and the DA are inseparable

25. Setting Up the DA
The DA setup takes place in NetWare Administrator/ConsoleOne®
Three new object classes in eDirectory
SLP Directory Agent
SLP Scope Unit
SLP Service

26. SLP Directory Agent Object
Required to load a DA on a NetWare server
Contains a link to the NCP server object
Contains a link to the SLP Scope Unit object serviced
Contains DA parameters
Cache limit
Purge hour

27. SLP Scope Unit Object Container to hold the SLP service information
Defines the SLP scope name
Understand the difference between the SLP scope name and the SLP Scope Unit object name
Can be partitioned

28. SLP Service Object Represents an SLP service that has been registered
Displayed as a URL
ndap.novell, bindery.novell, timesync.novell, etc.
Double-click to see various service attributes

29. Setting Up the DA Take default -or- Create the Scope Unit object(s)
Create the SLP Directory Agent object and link it to the Scope Unit object(s)
Load SLPDA at the NetWare server

30. DA Discovery Four ways a DA can discover another DA Multicast DHCP
Static
Through eDirectory (DAs only)

31. NetWare Server SLP Info
Critical NLMs
SLP.NLM
SLPTCP.NLM
SLPDA.NLM
Configuration files
SYS:ETC\SLP.CFG

32. Function of SLP.CFG SLP.CFG provides two functions
Static configuration of DAs on the network
SLP scope filtering

33. NetWare Server DA Discovery
Three ways to discover a DA on the network
Multicast
DHCP
Static

34. NetWare Server SLP Tuning
SLP tuning is performed through various SET parameters on the server
Several SLP set parameter changes require the server to be rebooted to take effect

35. NetWare Server SLP Tuning

36. NetWare Server Utilities
Four useful utilities for troubleshooting
SLP Debug
Display SLP DA
Display SLP Services
Display SLP Attributes

37. NetWare Client Info
Configuration of SLP on the NetWare client occurs in the properties page of the client
Accessed through the network control panel
Two panels for configuration
Service Location tab
Advanced Settings tab

38. Client DA Discovery
Three ways for a NetWare client to discover a DA on the network
Multicast
DHCP
Static

39. NetWare Client SLP Tuning

40. Client Troubleshooting Tools
SLPINFO
Windows 95/98—just run executable
Windows NT requires command line switches
SLPINFO [/d][/c][/o][/t][/s][/i][/a][/all][/h][/help]
/d displays information about known DAs
/c displays configured parameter settings
/o same as /c
/t displays configured timer values
/s displays known SLP scopes
/I displays local interface information
/a, /all displays all above listed options
/h, /help displays help screen

41. SLP Infrastructure Design
Use the KISS method when designing an SLP infrastructure
Understand what you are balancing
Client service resolution traffic
Service registration traffic
eDirectory synchronization traffic

42. SLP Infrastructure Design (cont.)
Two methodologies to SLP infrastructure design
Centralized
Regionalized
Understand the network topology and functional requirements of the organization
These will greatly affect the SLP infrastructure design

43. SLP Infrastructure Design (cont.)
DAs for large organizations should be dedicated to that function
A dedicated DA on a beefy box can handle 15,000–20,000 users by itself
Always have two DAs for fault tolerance

44. SLP Infrastructure Design (cont.)
Make the design efficient
Make the design scalable

45. SLP Implementation
Implement the designed infrastructure as soon as possible
Ideally, the first NetWare 5 server should be the directory agent
All future servers will contact the first NetWare 5 server for SLP services

46. Troubleshooting SLP Problems
How do you know when there is an SLP problem
Review the design
Review the versions of SLP running on the infrastructure
Review the technology—SLP may be working as designed

47. First Things First Make sure eDirectory is healthy
Make sure the servers and clients are properly configured
Make sure the directory agent is properly configured
Gather information about the environment

48. Use the DEBUG Utilities
Remember your DEBUG utilities on the client and the server
SLPINFO
SET SLP DEBUG
DISPLAY SLP DA
DISPLAY SLP SERVICES

49. Pulling Out the Big Gun . . .
If you think you have a problem that is not resolvable through reconfiguration, go to the best source of information available…the sniffer
A packet trace is the only true way to understand what is happening on the wire between UAs, SAs and DAs on the network

50. Understanding Packet Traces
Key pieces of knowledge required to understand packet traces
Thorough understanding of SLP
Thorough understanding of TCP/IP
It might look cryptic, but it can be easily understood with a little practice

51. Queue the Packet Traces
We will walk through a number of packet traces here
Packet analysis is fun

52. Real World Experiences
Things you might want to look for
eDirectory synchronization problems
DA discovery through DHCP
Corrupt clients

53. The DA on Windows NT/2000 Windows NT/2000 Directory Agent available
Comes packaged with eDirectory 85.00
Has features above and beyond NetWare DA
No SLP v2 support

54. Windows NT/2000 DA Installation
Steps to install the Windows NT/2000 DA
Run SETUP.EXE from the nt directory of the eDirectory install
Select SLP Directory Agent from the list of options
Click Install
Wait for client update to finish
SLP Directory Agent install program starts

55. Windows NT/2000 DA Installation

56. Windows NT/2000 DA Installation

57. Windows NT/2000 DA Installation

58. Windows NT/2000 DA Installation

59. Windows NT/2000 DA Installation

60. Windows NT/2000 DA Installation

61. Configuring the Windows NT/2000 DA
Directory Mode
Functions with eDirectory
Management and configuration is the same as the NetWare DA
DA configuration is stored within eDirectory
Use ConsoleOne to administer the Windows NT/2000 DA

62. Configuring the Windows NT/2000 DA
Local mode
Icon added to Windows NT/2000 Start Menu
Programs  Novell SLP Directory Agent
Select SLP DA Properties
Local mode DA configuration information
No information stored in eDirectory
Information stored in local NT/2000 registry

63. Configuring the Windows NT/2000 DA

64. Configuring the Windows NT/2000 DA

65. Windows NT/2000 DA Design Considerations
Local mode affects SLP infrastructure design considerations
Proxy mode allows the DA to pull information from an authoritative source on a periodic basis
No eDirectory synchronization impact felt during process
Service registration must be more carefully planned
Client configuration must be carefully planned and implemented

66. Windows NT/2000 DA Design Considerations
Proxy mode is like a DNS zone transfer
DA is given an authoritative source
Transfer happens on a periodic basis
One-way propagation of information

67. Understanding the DA Proxy
Periodic Request for SLP Information
Transfer of Known Services
Proxy DA
Authoritative DA

68. Configuring the DA Proxy
Click on the Properties tab from the Scopes tab after the appropriate scope has been highlighted
Format of the proxy command is
<scope_auth> [/<refresh_int>] [/<char_enc>] [/<target_scope>]

69. Configuring the DA Proxy
Important variables for proxy configuration
Scope authority is the DNS name or IP address of authoritative DA
Refresh interval is the time in minutes after which information should be retrieved
Character encoding is the character set that will be used when retrieving service information
Target scope is the name of the scope to be queried

70. Configuring the DA Proxy

71. Other Windows NT/2000 DA Features
Additional features of Windows NT/2000 DA include
Scope filtering
Private mode