howto://add the Telnet client to Windows 10

Just a quick reminder to myself on how to enable the Telnet Client in Windows 10, since I always seem to forget.

  1. Open an administrative command prompt.
  2. Run this command
    dism /online /enable-feature /featurename:telnetclient
  3. Done. It will be immediately available, even in existing, non-admin command prompts you already have open.

If you want to test it out, try this! telnet://

30 second movie review of Spectral

If you’re a Netflix subscriber, you’ve probably seen Spectral as one of your “Top Picks.” It’s actually a Universal production with some real acting talent, great special effects, and decent writing that, for whatever reason, Universal opted not to distribute. So Netflix picked it up.

There’s a fun mix of special forces action, science fiction, and ghost story all mixed in together, and well worth a rainy Saturday afternoon. Check out the trailer, then add it to your watchlist.


howto://disable hibernation in Windows

In case you don’t ever plan to have your computer hibernate, and would like to buy back the disk space wasted reserved by hiberfil.sys, it’s pretty simple to fix this.

  1. Open an administrative command prompt
  2. Run this command
    powercfg /hibernate off
  3. Profit 🙂

howto://set a Windows Server 2016 Hyper-V host to use SNTP for time sync

set your server to sync to NTP by running these commands.

w32tm /config /syncfromflags:MANUAL / /reliable:yes /update

net stop w32time && net start w32time

So I’m in the process of (re)setting up my lab, using a pair of multi-proc servers running Hyper-V to host my VMs. These will be member servers, which would normally get their time from a PDC in their domain. Of course, DCs normally need to get their time from a reliable time source, but as VMs, mine would get their time from the host servers on which they run. I could have changed the DCs of course, but instead opted to make those physical systems more reliable. That’s what this post is all about. Continue reading “howto://set a Windows Server 2016 Hyper-V host to use SNTP for time sync”

Miss me?

and we’re back. After some unavoidable hosting issues ended the previous incarnation of retrohack, I seriously, considered just letting it go. I mean, I wasn’t spending that much time on it, hadn’t in years, had gone months between posts, and really didn’t think anyone cared. Then two things happened. The first was that I got an email from someone who actually missed the site, and who said some very nice things about it. Then, I needed to enable stealth mode on Skype again, and couldn’t remember how to do it. Thank the gods for, which seems to have a copy of most of my old content. So, as time and interest allows, I will try to recreate some of the old posts from the website formerly known as, and who knows, maybe I will even add some new ones. Stay tuned, or not, as you see fit :-). And if there’s actually a post you’d like to see, use the contact form to let me know and I will try to nudge it up to the front of the queue.

subnet-wildcard values

CIDR SubnetMask     WildcardMask   HexSubNetMas
29 FF.FF.FF.F8
28 FF.FF.FF.F0
27 FF.FF.FF.E0
26 FF.FF.FF.C0
25 FF.FF.FF.80
24 FF.FF.FF.00
23 FF.FF.FE.00
22 FF.FF.FC.00
21 FF.FF.F8.00
20 FF.FF.F0.00
19 FF.FF.E0.00
18 FF.FF.C0.00
17 FF.FF.80.00
16 FF.FF.00.00
15 FF.FE.00.00
14 FF.FC.00.00
13 FF.F8.00.00
12 FF.F0.00.00
11 FF.E0.00.00
10 FF.C0.00.00
9 FF.80.00.00
8 FF.00.00.00
7 FE.00.00.00
6 FC.00.00.00
5 F8.00.00.00
4 F0.00.00.00
3 E0.00.00.00
2 C0.00.00.00


smtp response codes

code meaning                                                          
211 System status or system help reply
214 Help message
220 Service ready
221 Service closing transmission channel
250 Requested mail action okay
251 User not local will forward to
252 Cannot VRFY user but will take message and attempt delivery
253 messages pending for node started
354 Start mail input end with
355 Octet-offset is the transaction offset
421 Service not available
432 A password transition is needed
450 Requested mail action not taken: mailbox unavailable
451 Requested action aborted: local error in processing
452 Requested action not taken: insufficient system storage
453 You have no mail
454 TLS not available due to temporary reason
458 Unable to queue messages for node node
459 Node node not allowed: reason
500 Syntax error
501 Syntax error in parameters or arguments
502 Command not implemented
503 Bad sequence of commands
504 Command parameter not implemented
521 Machine does not accept mail
530 Must issue a STARTTLS command first
550 Requested action not taken: mailbox unavailable
551 User not local please try forwardpath
552 Requested mail action aborted: exceeded storage allocation
553 Requested action not taken: mailbox name not allowed
554 Transaction failed


Enhanced error codes

code meaning                                                                
x.1.0 Other address status
x.1.1 Bad destination mailbox address
x.1.2 Bad destination system address
x.1.3 Bad destination mailbox address syntax
x.1.4 Destination mailbox address ambiguous
x.1.5 Destination mailbox address valid
x.1.6 Mailbox has moved
x.1.7 Bad sender’s mailbox address syntax
x.1.8 Bad sender’s system address
x.2.0 Other or undefined mailbox status
x.2.1 Mailbox disabled, not accepting messages
x.2.2 Mailbox full
x.2.3 Message length exceeds administrative limit
x.3.0 Other or undefined mail system status
x.3.1 Mail system full
x.3.2 System not accepting network messages
x.3.3 System not capable of selected features
x.3.4 Message too big for system
x.4.0 Other or undefined network or routing status
x.4.1 No answer from host
x.4.2 Bad connection
x.4.3 Routing server failure
x.4.4 Unable to route
x.4.5 Network congestion
x.4.6 Routing loop detected
x.4.7 Delivery time expired
x.5.0 Other or undefined protocol status
x.5.1 Invalid command
x.5.2 Syntax error
x.5.3 Too many recipients
x.5.4 Invalid command arguments
x.5.5 Wrong protocol version
x.6.0 Other or undefined media error
x.6.1 Media not supported
x.6.2 Conversion required and prohibited
x.6.3 Conversion required but not supported
x.6.4 Conversion with loss performed
x.6.5 Conversion failed

netbios name types

code type meaning
0 U Workstation Service
0 G Domain Name
1 U Messenger Service
3 U Messenger Service
6 U RAS Server Service
1B U Domain Master Browser
1C G Domain Controllers
1D U Master Browser
1E G Browser Service Elections
1F U NetDDE Service
20 U Server Service
20 U DCA IrmaLan Server Service
21 U RAS Client Service
22 U Microsoft Exchange Interchange
23 U MS Exchange Store
24 U MS Exchange Directory
2B U Lotus Notes Server Service
2F G Lotus Notes
30 U Modem Sharing Server Service
31 U Modem Sharing Client Service
33 G Lotus Notes
43 U SMS Clients Remote Control
44 U SMS Administrators Remote Control
45 U SMS Clients Remote Chat
46 U SMS Clients Remote Transfer
4C U DEC Pathworks TCPIP Service
52 U DEC Pathworks TCPIP Service
6A U Microsoft Exchange IMC
87 U Microsoft Exchange MTA
BE U Network Monitor Agent
BF U Network Monitor Application
< \\–__MSBROWSE__> 01 G Master Browser

kerberos response codes

code message meaning
0x6 KDC_ERR_C_PRINCIPAL_UNKNOWN: Client not found in Kerberos
0x7 KDC_ERR_S_PRINCIPAL_UNKNOWN: Server not found in Kerberos
0x8 KDC_ERR_PRINCIPAL_NOT_UNIQUE: Multiple principal entries in
0xA KDC_ERR_CANNOT_POSTDATE: Ticket not eligible for postdating
0xC KDC_ERR_POLICY: KDC policy rejects request
0xD KDC_ERR_BADOPTION: KDC cannot accommodate
requested option
0xE KDC_ERR_ETYPE_NOTSUPP: KDC has no support for
encryption type
0xF KDC_ERR_SUMTYPE_NOSUPP: KDC has no support for
checksum type
0x12 KDC_ERR_CLIENT_REVOKED: Clients credentials have
been revoked
0x17 KDC_ERR_KEY_EXPIRED: Password has expired change
password to reset
0x19 KDC_ERR_PREAUTH_REQUIRED: Additional pre-authentication
0x1B KDC_ERR_MUST_USE_USER2USER: principal valid for
user2user only
0x1C KDC_ERR_PATH_NOT_ACCEPTED: KDC Policy rejects transited
0x1D KDC_ERR_SVC_UNAVAILABLE: A service is not available
0x1F KRB_AP_ERR_BAD_INTEGRITY: Integrity check on decrypted
field failed
0x20 KRB_AP_ERR_TKT_EXPIRED: Ticket expired
0x21 KRB_AP_ERR_TKT_NYV: Ticket not yet valid
0x22 KRB_AP_ERR_REPEAT: Request is a replay
0x23 KRB_AP_ERR_NOT_US: The ticket isn’t for us
0x24 KRB_AP_ERR_BADMATCH: Ticket and authenticator
don’t match
0x25 KRB_AP_ERR_SKEW: Clock skew too great
0x29 KRB_AP_ERR_MODIFIED: Message stream modified
0x34 KRB_ERR_RESPONSE_TOO_BIG: Response too big for UDP,
retry with TCP
0x3C KRB_ERR_GENERIC: Generic error