ipv6: difference between tracepath6 and scamper output

> I took a look at the tracepath information you sent for these nodes,
> which showed a bunch of unresponsive nodes but no information that
> might be useful for assigning blame.  It’d be cool to see these paths
> with scamper’s pmtud traceroute, which tries to find out the MTU for
> the hops that aren’t sending a PTB.
>
> with that list of IP addresses:
> scamper -c “trace -P udp-paris -M” -f <file>

though I used:

(for i in `cat f`; do echo “==================== $i”; tracepath6 -n $i; scamper -I “trace -P udp-paris -M $i”; done) >>f.out

This to show the difference between tracepath6 and scamper output, there are some to be seen, some quite scary (eg the 1455 change).
Could be that one just gets through the ICMP ratelimits in one run and not the other.

Those nodes are just blackholes it seems. Only the operators of that network will know what is going on.

I am always surprised to see networks filtering out packets, and especially wonder what they are trying to achieve with such a filter.

> http://www.caida.org/tools/measurement/scamper/
> http://www.caida.org/~mjl/pubs/debugging-pmtud.imc2005.pdf
>
> Happy to help anyway I can (I wrote scamper)

I am quite aware. Great tool, but not very verbose unfortunately. Hence, typically it just does/outputs nothing.

Greets,
Jeroen

ipv6 RA’s for learning default gateway for end systems (hosts)

> RA’s (router advertisements, aka, icmpv6 type 134)..
>
> Is the receipt of RA’s the only dynamic/automatic way for IPv6 clients to
> learn about their default gateway?
>
> Does DHCPv6 allow for default router option?  What are other ways to get
> default router into a ipv6 cpe ?

Right now, RAs and statically setting the info are the only way to do it.
DHCPv6 does not have a default router option.  Different people will have
different opinions on whether or not this is a fundamental flaw in the
design of DHCPv6.

IPv6; MTU Problem?

> Can you pass me along a traceroute6 to 2a02:26f0:6a:18f::eed and I’ll pass
> it along to the Akamai NOC?
scamper is your friend here:

> cheesecake# scamper -I “trace -P udp -M 2a02:26f0:6a:18f::eed”
> traceroute from 2a03:8900:0:100::5 to 2a02:26f0:6a:18f::eed
>  1  2a03:8900:0:100::1  0.216 ms [mtu: 1500]
>  2  2a02:8900:0:200::209  0.216 ms [mtu: 1500]
>  3  2a01:258:8:3::1  0.634 ms [mtu: 1500]
>  4  2001:1900:5:2:2::2dd9  1.053 ms [mtu: 1500]
>  5  2001:1900:5:1::319  12.990 ms [mtu: 1500]
>  6  2001:1900:5:1::412  12.926 ms [mtu: 1500]
>  7  2001:1900:5:3::21e  11.290 ms [mtu: 1500]
>  8  2001:41a8:600::1e  26.975 ms [mtu: 1500]
>  9  2001:41a8:600:2::b6  27.529 ms [mtu: 1500]
> 10  *
> 11  2a02:26f0:6a::210:d9a3  25.227 ms [mtu: 1500]
> cheesecake#

This means no path mtu problems from as1197 to 2a02:26f0:6a:18f::eed.

Nick

 

Uitschakelen Windows tunnel interfaces

https://www.asmus-consulting.com/en/blog-category-active-directory-and-windows-server/item/41-disable-ipv6-tunnel-adapter

Use these 3 lines to disable the Adapters by netsh:

1 netsh int ipv6 isatap set state disabled
2 netsh int ipv6 6to4 set state disabled
3 netsh interface teredo set state disable



You can also disable Tunnel Adapters by GPO
– open Group Policy Management Editor
– select an existing or create a new GPO
– Computer Configuration -> Administrative Templates -> Network -> TCPIP Settings -> IPv6 Transition Technologies






Configure all of the Settings below – enable the Setting but select “disable” within.
– “Set 6to4 State”
– “Set ISATAP State”
– “Set Teredo State”









thats it

Netflow viewers

FlowViewer / SiLK handles IPv6.

Web-based, graphical tracking and analysis. Free.

http://sourceforge.net/projects/flowviewer/

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/3se/flexible_netflow/configuration_guide/b_fnf_3se_3850_cg/b_fnf_3se_3850_cg_chapter_010.html#reference_A9019899140647F2B3F87ABABCFC170D

http://qosient.com/argus/

IPv6 security

MAC bindings

In the IPv4 world, the DHCP server allocates IPv4 addresses and thereby stores the MAC addresses of the clients. In the IPv6 world, if SLAAC (autoconfiguration) is used, no network or security device per se stores the binding between the MAC (layer 2) and the IPv6 (layer 3) addresses from the clients. That is, a subsequent analysis of network behaviour corresponding to concrete IPv6 addresses and their client machines is not possible anymore.

6MoN

is a network monitoring software developed to detect the behavior of hosts on big LANs. By its nature can be an aid for the network administrator to identify anomalies on a LAN. The tool is able to identify the presence of a node indicating the association between MAC, IPv4 and IPv6 address, maintains an history of network access and any changes in presence of mechanisms for automatic address assignment (DHCP, SLAAC ).

ipv6mon

is a tool meant for monitoring IPv6 address usage on a local network. It is meant to be particularly useful in networks that employ IPv6 Stateless Address Auto-Configuration (as opposed to DHCPv6), where address assignment is decentralized and there is no central server that records which IPv6 addresses have been assigned to which nodes during which period of time.

ipv6mon employs active probing to discover IPv6 addresses in use, and determine whether such addresses remain active.

NAV

is an acronym for Network Administration Visualized. It is an advanced software suite to monitor large computer networks. It automatically discovers network topology, monitors network load and outages, and can send alerts on network events by e-mail and SMS, allowing for flexible configuration of alert profiles.

NDPmon

 is a diagnostic software application used by Internet Protocol version 6 network administrators for monitoring ICMPv6 packets. NDPMon observes the local network for anomalies in the function of nodes using Neighbor Discovery Protocol (NDP) messages, especially during the Stateless Address Autoconfiguration. When an NDP message is flagged, it notifies the administrator by writing to the syslog or by sending an email report. It may also execute a user-defined script. For IPv6, NDPMon is an equivalent of Arpwatch for IPv4, and has similar basic features with added attacks detection.

IPv6 uitzetten van ISATAP/Teredo

To disable isatap teredo and 6to4 on a Windows 7 workstation, type the following at the prompt. You do of course need Administrative access on the workstation to do this.

If like myself your running dual stack IPv6 via your router or gateway, then there is really no need to have them running.

netsh int ipv6 isatap set state disabled
netsh int ipv6 6to4 set state disabled
netsh interface teredo set state disable

To re-enable isatap teredo nd 6to4, just replace the disabled with enable using the commands above.

Bron:
http://www.dickson.me.uk/2012/03/20/ipv6-disabling-isatap-and-6to4-in-windows-7/

Cisco IPv6 IOS firewall

ipv6 inspect routing-header
ipv6 inspect max-incomplete low 100
ipv6 inspect max-incomplete high 300
ipv6 inspect one-minute low 100
ipv6 inspect one-minute high 300
ipv6 inspect udp idle-time 60
ipv6 inspect tcp idle-time 1200
ipv6 inspect tcp finwait-time 8
ipv6 inspect tcp synwait-time 60
ipv6 inspect tcp max-incomplete host 100 block-time 1
!
interface dialer X
!
ipv6 inspect name ipv6-FireWall tcp alert on timeout 120
ipv6 inspect name ipv6-FireWall udp alert on timeout 60
ipv6 inspect name ipv6-FireWall icmp alert on audit-trail on timeout 5
ipv6 inspect name ipv6-FireWall ftp timeout 3600
!

ipv6 verify unicast source reachable-via any allow-default
ipv6 inspect ipv6-FireWall in
ipv6 inspect ipv6-FireWall out
ipv6 traffic-filter ipv6-inet-in in
!
ipv6 access-list ipv6-inet-in
remark block site local
deny ipv6 any FEC0::/10
remark block mcast
deny ipv6 any FF00::/8
remark permit mcast link local
permit ipv6 any FF02::/16
remark permit mcast global scope
permit ipv6 any FF0E::/16
remark permit minimale icmp berichten
permit icmp any any echo-reply
permit icmp any any time-exceeded
permit icmp any any unreachable
permit icmp any any echo-request
permit icmp any any packet-too-big
permit icmp any any parameter-problem
permit icmp any any mld-query
permit icmp any any mld-report
permit icmp any any mld-reduction
permit icmp any any router-solicitation
permit icmp any any router-advertisement
remark permit toegestaan verkeer

 

Cisco IPv6 config (met DHCP)

ipv6 unicast-routing
ipv6 cef
!
interface dialer 1
ipv6 address A:B:C:3::1/64
!
interface BVI1
ipv6 address A:B:C:1::1/64
ipv6 enable
ipv6 nd managed-config-flag
ipv6 nd other-config-flag
ipv6 nd router-preference High
ipv6 dhcp server LAN rapid-commit
!
ipv6 dhcp pool LAN
address prefix A:B:C:1::/64
dns-server A:B::C
domain-name ipv6.org
information refresh 0 12

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