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Emulab Knowledge Base

Emulab Knowledge Base

Getting Started

  1. Who is Eligible to use Emulab.Net?
  2. How do I start a project?
  3. I'm a project leader and someone applied to join my project, but they are not on the list to be approved
  4. How do I join a project?
  5. Will Emulab send me email messages?
  6. I have an Emulab account. Now what?
  7. Can I be in more than one project?
  8. Can I change my Emulab password?
  9. I'm a project leader. Can I designate TAs?
  10. How do I report a specific problem?
  11. Where do I get more help?
  12. Forgot your password? Resetting does not work!
  13. How do I change my email address?

Customizing your experiment

  1. How to build your own delay kernel
  2. How do I build a custom Linux kernel?


  1. My experiment setup failed, what did I do wrong?
  2. My experiment is set up, but I cannot send packets between some of the nodes. Why?
  3. I asked for traffic shaping, but everything seems to be going at full LAN speeds
  4. I set a non-zero packet-loss (or delay) but 'ping' shows no packet-loss (or delay)
  5. I set a non-zero packet-loss (or delay) but 'ping' shows a different packet-loss (or delay)
  6. I decreased the bandwidth on a link and now the ping time between the nodes has increased
  7. I wrote a small TCP application to test the bandwidth of a link/LAN, but I do not observe the bandwidth that I asked for.
  8. I wrote a small UDP application to test the bandwidth of a link/LAN, but I do not observe the bandwidth that I asked for.
  9. I am running a routing daemon in my topology but the daemon claims that all my nodes are directly connected!
  10. My custom Linux kernel won't boot, why?
  11. Why is the per-packet latency so high (variable) on the pc3000 nodes?
  12. Why isn't my multicast traffic being correctly shaped?
  13. Why does my NS file not parse correctly anymore?
  14. I got an error in my swapin that says 'Temporary Resource Shortage' - what does it mean?
  15. I am running into errors while working in my home and/or project directory (or subdirectories). What's going on?
  16. What does the warning message 'due to delay implementation, odd delay value N for LAN may be rounded up' mean?
  17. My program agent command did not execute, why not?
  18. I get a WARNING message from linktest, what does it mean?
  19. How does Windows XP start up in Emulab?
  20. Not enough permission to create an experiment in any of your projects

Using the Testbed

  1. Is there a tutorial?
  2. Do you have a GUI to help me create experiments?
  3. Are there any constraints on my topology?
  4. How many nodes can I ask for?
  5. How long can I keep using my nodes?
  6. I only need a couple of nodes but none are free, should I just keep trying?
  7. What if I need more nodes than are free?
  8. Do I get root access on my nodes?
  9. Do my nodes have consoles I can look at?
  10. How do I connect directly to node consoles, without going through users?
  11. Can I reboot (power cycle) my nodes?
  12. I've clobbered my disk! Now what?
  13. Where do I store files needed by my experiment?
  14. Are my files on users backed up (filesaved)?
  15. Are the nodes in my experiment backed up (filesaved)?
  16. What is Swapping?
  17. How can I get switch statistics (such as packet counts) for my experiment?
  18. What names should I use to refer to the nodes in my experiment?
  19. Can I modify my experiment after creating it?
  20. Are there Linux and/or FreeBSD sources and packages available locally?
  21. How can I login to or a node in my experiment without providing my password?
  22. How much permanent disk is available for my files?
  23. Where are the Emulab command-line tools located?
  24. Can I specify specific network interfaces on the nodes for the links in my topology?
  25. So you want to teach a class using Emulab?
  26. Linking to Emulab from your project home page
  27. What topology generators work with Emulab?
  28. Isonet man page
  29. Resources Temporary Unavailable
  30. All things Java
  31. Why can't I swap in my N node experiment, when there are more than N nodes free?
  32. What is LinkTest
  33. Available network topological data
  34. Is there a Web Service interface for common emulab tasks?
  35. Features and Desires

Hardware Setup

  1. What kind of computers are used for my nodes?
  2. How many nodes are there?
  3. How many ethernet cards are on each node?
  4. How do I ask for specific hardware?
  5. How many nodes are currently available (free)?
  6. Can I do traffic shaping on my links?
  7. Can I modify the traffic shaping parameters on my links?
  8. Are there other traffic shaping parameters besides latency,bandwidth, and packet loss rate?
  9. Do any Emulab nodes have wifi (802.11) interfaces?
  10. What kind of wifi cards are used in Emulab?
  11. What does 'Too many links of type ethernet!' mean (and what do I do)?
  12. What is the current arrangement of switches and nodes?
  13. What is the control net and how do I identify it on a node?
  14. What are the limits for link shaping?
  15. Can I make a simplex link instead of a duplex link in an experiment?

Operations and Policy

  1. Restricted access for SIGCOMM'06
  2. What does testbed-ops message 'WARNING: power controller(s) failed with exit value N' mean?
  3. How do I swapout a firewalled experiment that is paniced or failed to swapout?
  4. How can I control what boots on a node?
  5. Citing Emulab in papers that use Emulab


  1. Building binaries for PlanetLab
  2. Moving back and forth between PlanetLab and Emulab
  3. Setting up a private PlanetLab inside Emulab
  4. Using PlanetLab nodes with a specific version in your experiment.

Security Issues

  1. Is Emulab Firewalled?

Setting Up a New Emulab

  1. What partitions do I have to make initially?
  2. Nodes not being reloaded
  3. How is the reboot timeout controlled?
  4. I've added new nodes to the testbed but I cannot ping them, what is wrong?
  5. How do I add users to arbitrary unix groups on boss/ops
  6. Python, Swig, and m2crypto incompatibilities
  7. Whats that Cross Reference Tag in the Knowledge Base entry used for?
  8. Whats that Faq Entry checkbox in the Knowledge Base entry used for?
  9. Does Emulab use NTP?
  10. Event system: elvin or pubsub?
  11. The node boot process (also known as PXE booting)

Software Setup

  1. What OS do the nodes run?
  2. How do I select which OS to run on each node?
  3. Is Windows 2000 supported as well as Windows XP?
  4. Can I load my own software (RPMs/Tarballs) on my nodes?
  5. Can I schedule programs to run automatically when a node boots?
  6. How can I turn on routing or set up routes automatically on my nodes?
  7. How does my software determine when other nodes in my experiment are ready?
  8. Can I run my own Operating System?
  9. Can I share a disk image between two projects?
  10. What if I need more disk space on my nodes?
  11. Are there testbed-specific daemons that could interfere with my experiment?
  12. Does Emulab support IP Multicast?
  13. Why does my image not boot on node type Y?
  14. What FreeBSD kernels are available and what features do they include?
  15. FreeBSD kernel sources, support for ipfw and dummynet
  16. Locking complaints during compilation
  17. What device drivers do I need in my operating system to run in Emulab?
  18. How is experiment idle monitoring done?
  19. Can I enable ALTQ on FreeBSD for strict priority and class-based queuing?
  20. How to build FreeBSD ports
  21. 64 Bit (x86_64) Fedora
  22. How do I create an image of second hard drive?

Collaboration Tools

  1. Who is the administrator of per-project mailing lists?

Emulab Source Code

  1. Read-Only Access to Emulab CVS
  2. Commit Access to Emulab CVS

Experiment Templates

  1. Template Parameters
  2. CVS Interface to the Workbench

Testbed Operations

  1. How can I clear machines classified dead?
  2. How can I change a project's head UID at approval time?
  3. How do I reserve nodes for maintenance?
  4. Understanding ImageID's and OSID's and defaults
  5. How do I diagnose NTP problems?
  6. How do I spot idle experiments?
  7. What are the groups of "active" users who are in no projects?
  8. How can I schedule OS reloads by PC type?
  9. What are the limitations on the "delete user" page?
  10. How do I find out about switch errors?
  11. How do I find out about experiments with idle_ignore set on?
  12. Comments on priority management while handling Tb-Ops mail.
  13. How do I set an Emulab banner for events like downtime?
  14. How do I turn on cvsweb access for a user?
  15. How do batch experiments signal finish status?
  16. What are sitevars?
  17. What history is kept for failed experiments?
  18. How do I control Idleswap and Autoswap e-mail?
  19. How do I maintain the node type table?
  20. How do I clear an experiment stuck in the "swapping" state?
  21. How do I control verbose syslogging in tmcd?
  22. What if "node health monitoring" complains at boot time?
  23. How do I mount the Linux slice in BSD?
  24. How do I approve a user when the project roots are out of town?
  25. What does "head user has not been verified" mean when approving a project?
  26. How do I see plab usage?
  27. What is a "recently-logged-in user"?
  28. What can I do about switch port problems?
  29. How do I turn off idleswap for a bunch of experiments?
  30. How does account freezing work?
  31. How do I grant permission to use types or classes of nodes?
  32. What do I do with nodes in "hwdown"?
  33. How do do you create special experiments with no ns file?
  34. What should I do when nodes hang in
  35. When is the dhcpd.conf file regenerated?
  36. How do we make special groups on Ops?
  37. How do we partition nodes administratively into multiple "types"?
  38. Why do I get an error from anything that does an RPC to boss?
  39. How do I change the id of a new user or project?
  40. How do I find out about ethernet devices on Linux?
  41. How do I deal with "Experiment Configure Failure"?
  42. How to boot an existing FreeBSD kernel with a different HZ.
  43. How do I forcibly terminate an experiment when things are wedged?
  44. Understanding FreeBSD Kernels on Disk Images
  45. What is the algorithm for determining whether a user has permissions to load an image?
  46. How to use nextosid for a level of indirection
  47. How can I regenerate ssh identity files?
  48. How do I move an Emulab to a new IP space?
  49. What are the primary issues that students should be aware of?
  50. What version of the OS does a previously swapped-in experiment use?
  51. How can I put nodes in hwdown state for hacking?
  52. If I mess up a node's disk partitions or something, how do I trigger a complete reinstall of that node?
  53. How do I restart tftpd?
  54. What does the "New" line mean in "Summary stats"?
  55. How do I transfer project_root status to my alter ego?
  56. How do I get nodes out of RELOADSETUP state?
  57. How do I deal with "Swap out Failure"?
  58. How do I restart "capture"?
  59. How to deal with stranded VLANs?
  60. What is the Emulab ethernet switch configuration?
  61. What does "invalid migration assumptions" mean from "assign"?
  62. How do I restart mysqld on boss?
  63. How can I change a project's head UID later on?
  64. What does "Node Checkin Error" mean?
  65. How do I deal with bad ports and Cisco switch trunking?
  66. How do I find out the virtual name of a PC given the physical name
  67. What happens if the experiment state is wiped out?
  68. What about serial connections to the Admin MFS FreeBSD?
  69. How do I diagnose Windows swap-in failures?
  70. How do I handle changes to the tmcd protocol and code?
  71. How are robot experiment swap-ins handled?
  72. How is vlan trunking supported on pc's?
  73. How do I clear Frisbee failures?
  74. How do I handle SNMPIT switch control errors?
  75. What do I do for robot nodes in hwdown?
  76. How do I tell if I left a firewall vlan on the switch?
  77. How do I deal with Frisbee "Device not configured" errors?
  78. How do I remove a new switch from the stack?
  79. How do I deal with switch "VLAN edit buffer request failed" errors?
  80. Where do I find a WIFI node with a serial console?
  81. How do I make Fedora Core images?
  82. What logging does trafgen do?
  83. Where can I see power and temperature monitor data?
  84. How is experimental switch trunk port bandwidth determined?
  85. Questions about node booting in Emulab.
  86. What happens when I free a node?
  87. How do I deal with a "PXE Failed" message?
  88. Serial console access doesn't work, but SSH does?
  89. How do I check whether frisbeed is running on boss?
  90. Problem with node booting okay but not recognized?
  91. Problem with "Assign Failed" error message?
  92. Problem with "Setting up for SFS" message?
  93. What is the "Load Address" of an OS image?
  94. How do I deal with an experiment left in the "swapping" state?
  95. What are the stages that the delay node goes through after the PXE wait?
  96. What do I do if mkproj fails in the middle?
  97. How do I remotely power cycle Ops?
  98. How are tipserv nodes represented in the nodes table?
  99. Problem getting hostname set, resulting in TBFAILED?
  100. How can I partially swap in an experiment for snmpit debugging?
  101. How do I clean up orphaned VLANs?
  102. How does Emulab find the control interface on Linux?
  103. How do I get an updated image loaded in an experiment, or globally?
  104. How many VLANs should be created for an experiment?
  105. How do I grant RON node access to a project?
  106. How do I force a reload of everything in "reloading"?
  107. How do I handle failed swapouts?
  108. How do I set a policy to restrict swapins during crunch times?
  109. How do I handle "Failed to start the event system" errors?
  110. How do I turn off idle detection?
  111. How do I add group "wheel" access for help from Utah on my Emulab?
  112. How do I administer a per-project mailing list?
  113. Problem with IP addresses not being configured.
  114. What does "Could not remove project" mean?
  115. How do I cross-reference Knowledge Base entries?
  116. Where are messages from the Cisco switches logged?
  117. Problems with switches dropping out of the switch stack.
  118. How do I grant access to the Emulab Mobile Wireless Testbed.
  119. How do I enable multicast for Frisbee on router interfaces?
  120. How do I rename a project?
  121. How can I control the Reserved Nodes list on the Experiment info page?
  122. How do I find out switch port info for a given node?
  123. Gig-e links on Ops.
  124. How do I see interface error counts?
  125. What can cause NFS mount failures to fs/ops?
  126. How do I check for partial switch setup/teardowns?
  127. How do I deal with "ERROR - unable to find channel information"?
  128. Why is switch cisco8 special?
  129. Where do I find NFS trace logs?
  130. Is there a backdoor to log in to the web interface when nologins is set?
  131. How do we prevent spam on the Emulab mailing lists?
  132. How do I reserve nodes for an experiment in bulk?
  133. Problem with nodes getting stuck in an infinite loop under os_load
  134. What can cause topomap write failures to prevent swap-in?
  135. When do trunks show up on a control-net switch?
  136. Logging of testbed errors to their own list under Tblog
  137. How long do user transaction keys last?
  138. What can cause the Boss CVS tree to get out of date?
  139. How do I deal with a non-existent experiment with allocated nodes?
  140. Problem with os_load
  141. How do I deal with warnings that "Linktest is already running"?
  142. What is the purpose of "/tftpboot/proj" ?
  143. What's special about NTP on PLAB-DEVBOX?
  144. Problem with events not firing on plab nodes.
  145. Problem with a Linux frisbee image coming up in FreeBSD.
  146. Problem with Elab mail mgmt of elabft-discussion list
  147. Problem with bad switch module again?
  148. Experiments Stuck in Transistion
  149. Can I change the project leader of a project
  150. What does "Inconsistent lastrsrc in stats record" mean?
  151. How can I fix my broken GRUB install?