Why is iSCSI Trying to Connect on IPv6 at boot?

18.04.02

I recently added an iSCSI target (Synology Diskstation). It mounts just fine at each boot; however, many times, boot time hangs and the only thing I really see that may be causing it is many errors that look like the following:

cannot make a connection to fe80::211:32ff:fe1e:66fc:3260 (-1,22) 

I cannot for the life of me figure out why this is happening. I disabled ipv6 by doing the following:

net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1 

Running

cat /proc/sys/net/ipv6/conf/all/disable_ipv6 

Returns 1, so I know it is disabled and persists through boot.

I have searched for a couple of days andD all I can come up with is a bug report from like 10 years ago so surely that can’t be the reason, could it? Any other ideas are appreciated. Normally, I would just ignore it, but I am not sure that it isn’t what is causing the hang.

iOS 12 (iPad) Scoped literal IPv6 addresses

I have a raspberry pi running dnsmasq on my lan with both IPv4 and IPv6. I would like to use the custom dns setting on the iPad to use the raspberry rather than the DNS offered by the router in DHCP and router announcement, (I don’t want everything on my lan to use the pi). I can’t use the global IPv6 address of the Pi because I do not have a static IPv6 subnet.

On my computer I am able to use the fe80 link-local address, but it does not work on the iPad. I am thinking I need to specify a zone index, but I don’t know what it would be. I tried appending %en0 but that did not work.

Is it possible to specify the zone index on iOS, and if so, what format is used?

(Using terminology from Wikipedia IPv6 article)

Ubuntu SSH connection hangs when I run ifconfig with IPv6 enabled

I’ve been playing around with IPv6 and setup a DigitalOcean droplet. The only difference between now and before is that I told it to setup IPv6. More often than not, when I run ifconfig the SSH session hangs, then disconnects due to unresponsiveness. The ifconfig command doesn’t finish when this happens…it only gets past dumping the IPv6 details.

Any place I can check to debug this? My solution right now is just not to run ifconfig.

What issues would arise if I decide to move my local network to IPv6?

I am managing a small corporate network, and actively investigate the possibility of getting rid of IPv4 entirely, at least on the LAN level. I intend to disable IPv4 DHCP and connect to each machine using their IPv6 addresses.

All of my devices support IPv6. My ISP is currently running dual stack (IPv4 + IPv6). What issues would arise if I decide to move my local network to IPv6?

Here are my efforts so far:

  1. I bought a static IP address (fyi it costs additional money in my country) and my ISP gave me a static IPv4 one. My public IPv6 address still changes after a router reboot. I asked for a static v6 address but the technical support couldn’t help. They said they were running IPv6 on top of IPv4 or something like that.
  2. If I change the WAN connection in my router from the default IPv4 + IPv6 to IPv4 only, it works. But if I set it to IPv6 only, I cannot connect to the Internet. I don’t know why yet.
  3. By disabling IPv4 support from Windows Network Adapter Properties, web browsers start looking for AAAA DNS records. Most websites still use A record, and do not have AAAA record (maybe because they don’t have static IPv6 address for it). The web browser cannot fall back to IPv4 option, and the domain names cannot be resolved.

Is it practical to use IPv6 exclusively on LAN as of now?

configure IPv6 address on interface with static IID

I’m looking for a tool, very much like rdisc6, that will, having received the RA, will configure the v6 address(es) on an interface using a static IID. This is a server that needs to be at a known address within a ULA. (No, I can’t use mDNS and SLAAC, as there are certificates bound to names involved, and mDNS may not even work until this interface is configured).
If I have to, I’ll extend rdisc6, but I’m hoping not to replicate something someone already did. This will be running on Linux (armv7) inside an LXC container.

Force SQL Server 2019/Ubunti to use ipv4 instead of ipv6

We are testing usability of Microsoft’s SQL Server on Linux servers for our internal products, and we ran into a bump during config. We are trying to setup and configure SQLServer 2019 (preview) and we managed to setup the repo and install the sql server binaries from it. However, when we run sudo /opt/mssql/bin/mssql-conf setup and choose edition, it stalls for a while and errors out. The log shows:

2019-05-21 14:07:57.08 spid22s     Error: 26024, Severity: 16, State: 1. 2019-05-21 14:07:57.08 spid22s     Server failed to listen on 'any' <ipv6> 1433. Error: 0x2742. To proceed, notify your system administrator. 2019-05-21 14:07:57.08 spid22s     Error: 17182, Severity: 16, State: 1. 2019-05-21 14:07:57.08 spid22s     TDSSNIClient initialization failed with error 0x2742, status code 0xa. Reason: Unable to initialize the TCP/IP listener. A socket operation encountered a dead network.  

The culprit is obvious, setup attempts to start the server on <ipv6>, which we, for reasons unrelated to this, have disabled on production boxes. We need SQL Server to setup and run on <ipv4> and I don’t seem to see any way to change that using mssql-config, as per mssql-config instructions.

Has anyone had any experience setting this up?

Show delegated ipv6 prefix at command line in OpenWRT

In OpenWRT’s gui “LuCI“ the delegated IPv6 Prefix provided by the ISP is diplayed in the status page in overview. Normally it will be shown under “IPv6 WAN Status“ in the “Network“ section like

IPv6 WAN Status  Type: dhcpv6-pd                  Prefix Delegated: 2001:db8:1234:5678::/56                  Address: 2001:db8::abcd/128                  […] 

However I would like to figure out the delegated prefix on the command line. I am aware I can get the addresses assigned via ip a or the gateway and other routes via ip r but never manged to retrieve the prefix delegated by the router.

How can I show the delegated ipv6 prefix in the command line interface? Is there a command I am missing or some file it is written into that I am not aware of?