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phpmacosactive-directoryldapdomaincontroller

Mac OS X slow connections - mdns 4-5 seconds - bonjour slow

I'm finally at my wits end. I've been Googling this issue for a week now. I've tried troubleshooting my Mac (10.12 Sierra) and my domain controllers (Windows Server 2016) and I am no closer to solving my issue.

My issue is that when using PHP's ldap_connect() function, it takes about 5 seconds before I get a response. Things just sort of hang for 5 seconds then I get a successful connection. The exact command to replicate this (assuming my DC has an IP address of 192.168.2.5):

$ldap = ldap_connect('ldap://192.168.2.5:389');

I'm not using SSL or TLS. It's just a simple plaintext connection to a DC with its firewall completely turned off. I ended up installing Wireshark on my DC to get more information with what is going on and I noticed this:

No. | Time | Source | Destination | Protocol | Length | Info

1 | 327 | 192.168.2.108 | 224.0.0.251 | MDNS | 83 | Standard query 0x0000 A Ryans-MacBook-Pro.local, "QU" question

2 | 328 | 192.168.2.108 | 224.0.0.251 | MDNS | 83 | Standard query 0x0000 A Ryans-MacBook-Pro.local, "QM" question

3 | 331 | 192.168.2.108 | 224.0.0.251 | MDNS | 83 | Standard query 0x0000 A Ryans-MacBook-Pro.local, "QM" question

4 | 332 | 192.168.2.108 | 192.168.2.5 | TCP | 78 | 49860 > 389 [SYN] Seq=0 Win=65535 Len=0 MSS=1460 WS=32 TSval=371626102 TSecr=0 SACK_PERM=1

5 | 332 | 192.168.2.5 | 192.168.2.108 | TCP | 74 | 389 > 49860 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1 TSval=2494847497 TSecr=371626102

6 | 332 | 192.168.2.108 | 192.168.2.5 | TCP | 66 | 49860 > 389 [ACK] Seq=1 Ack=1 Win=131744 Len=0 TSval=371626102 TSecr=2494847497

7 | 332 | 192.168.2.108 | 192.168.2.5 | LDAP | 96 | bindRequest(1) "ldap" simple

8 | 332 | 192.168.2.5 | 192.168.2.108 | LDAP | 88 | bindResponse(1) success

As you can see, when I initiate the ldap_connect() function, I immediate see the first packet at 327 seconds (since running Wireshark). I see 3 mdns packets for a total of 5 seconds. Then on the fourth, fifth and sixth packets I see the TCP three-way handshake and then it continues to give me a successful ldap connection. Therefore the 5 second delay I'm seeing is all mdns packets or Apple's Bonjour? At this point, I have no idea how to fix this.

Disclaimer: I am using Laravel Valet which uses dnsmasq. I have no idea if this is causing my issue or not. I have not uninstalled this software yet to find out.

edit: I've ruled out Laravel Valet. I completely uninstalled it and it's still an issue. I've also ruled out Laravel. I'm running this script and the issue still exists:

<?php

$start = microtime(true);

$ldap = ldap_connect('ldap://192.168.2.5:389');

$end = microtime(true);

echo $end - $start;

edit2: Ok I've gotten further with solving this. I installed Wireshark on my Mac and noticed the below as well.

enter image description here

Then I ran this command: ➜ ~ scutil --dns DNS configuration

resolver #1
  search domain[0] : corp.[redacted].com
  nameserver[0] : 192.168.2.4
  nameserver[1] : 192.168.2.5
  if_index : 7 (en3)
  flags    : Request A records
  reach    : Reachable, Directly Reachable Address

resolver #2
  domain   : local
  options  : mdns
  timeout  : 5
  flags    : Request A records
  reach    : Not Reachable
  order    : 300000

It's my hostname! My hostname is causing a 5 second delay trying to resolve it using multicast DNS. Why? .local is a reserved domain so why would Apple append it to my hostname?

enter image description here

As you can see, it automatically appends .local.

Anyway, I've resolved my issue by adding 127.0.0.1 Ryans-MacBook-Pro.local to my /etc/hosts file. For some reason it wasn't in there.

My ldap_connect() is now instant like it should be!

Solution

  • Make sure your hostname is in the /etc/hosts file like this:

    127.0.0.1 localhost Ryans-MacBook-Pro.local

    Just replace my hostname with yours.