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April 18th, 2020 06:00
VLT peer-routing SLAAC
Hello,
I have a question regarding VLTi with peer-routing in an IPv6
environment using SLAAC.
What is the recommended configuration in this case?
I can only find documents for IPv4 configurations.
I already did the following tests:
1. Different IPv6 addresses on the interface with VRRP:
TOR1:
-----
interface vlan10
no shutdown
ipv6 address 2001:db8::1/64
ipv6 address fe80::1/64 link-local
ipv6 nd max-ra-interval 60
ipv6 nd ra-lifetime 180
ipv6 nd send-ra
vrrp-ipv6-group 10
virtual-address fe80::3
no preempt
TOR2:
-----
interface vlan10
no shutdown
ipv6 address 2001:db8::2/64
ipv6 address fe80::2/64 link-local
ipv6 nd max-ra-interval 60
ipv6 nd ra-lifetime 180
ipv6 nd send-ra
vrrp-ipv6-group 10
virtual-address fe80::3
no preempt
Here the host gets two default routes (fe80::1 and fe80::2) since the
source address of
the RA is always the link-local address of the sending switch.
Is there a way to use fe80::3 as the source address in RAs?
In this case the receiving hosts should use this address as their default route.
2. Same ipv6 address configuration for both switches:
TOR1:
-----
interface vlan10
no shutdown
ipv6 address 2001:db8::1/64
ipv6 address fe80::1/64 link-local
ipv6 nd max-ra-interval 60
ipv6 nd ra-lifetime 180
ipv6 nd send-ra
TOR2:
-----
interface vlan10
no shutdown
ipv6 address 2001:db8::1/64
ipv6 address fe80::1/64 link-local
ipv6 nd max-ra-interval 60
ipv6 nd ra-lifetime 180
ipv6 nd send-ra
Here only the host gets one default route, but both switches share the
same IPv6 addresses, which is, at least in an IPv4 configuration, not
recommended.
Would such a configuration be OK in the IPv6 case?
Thanks in advance.
DELL-Josh Cr
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April 20th, 2020 10:00
Hi,
Is it working with them both being the same?
DELL-Josh Cr
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April 22nd, 2020 14:00
Which model switch is it? What OS version?
DorfPinguin
8 Posts
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April 22nd, 2020 14:00
Hi,
thanks for your reply.
Unfortunately it does not work. The switches do not send RAs, if both have the same address.
DorfPinguin
8 Posts
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April 22nd, 2020 15:00
It is currently a test deployment on GNS3.
Dell EMC Networking OS10 Enterprise
Copyright (c) 1999-2020 by Dell Inc. All Rights Reserved.
OS Version: 10.5.1.0
Build Version: 10.5.1.0.124
Build Time: 2020-02-12T09:05:20+0000
System Type: S4128F-VM
Architecture: x86_64
Maybe I can test it tomorrow on two physical S4148T-ON.
DorfPinguin
8 Posts
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April 23rd, 2020 15:00
Hi,
I have tested the configuration on two physical S4148T-ON and got the same results.
After the initial configuration everything works fine, both switches send RAs but after a reboot they
stop sending RAs. To re-enable it, i have to run "no ipv6 na send-ra" and after that "ipv6 ra send-ra"
on the interface.
Because of the following messages I thought that this is related to ipv6 DAD:
2020-04-22T22:56:50.734120+00:00 TOR2 dn_alm 830 - - Node.1-Unit.1:PRI [event], Dell EMC (OS10) %IPV6_DAD_FAILURE: IPv6 Duplicate Address Detected! IPv6 DAD failed on vlan10
2020-04-22T22:56:50.798717+00:00 TOR2 dn_alm 830 - - Node.1-Unit.1:PRI [event], Dell EMC (OS10) %IPV6_DAD_FAILURE: IPv6 Duplicate Address Detected! IPv6 DAD failed on vlan10
2020-04-22T22:56:50.889354+00:00 TOR2 dn_alm 830 - - Node.1-Unit.1:PRI [event], Dell EMC (OS10) %IPV6_DAD_FAILURE: IPv6 Duplicate Address Detected! IPv6 DAD failed on vlan10
2020-04-22T22:57:50.932265+00:00 TOR2 dn_alm 830 - - Node.1-Unit.1:PRI [event], Dell EMC (OS10) %IPV6_DAD_FAILURE: IPv6 Duplicate Address Detected! IPv6 DAD failed on vlan10
2020-04-22T22:57:51.461894+00:00 TOR2 dn_alm 830 - - Node.1-Unit.1:PRI [event], Dell EMC (OS10) %IPV6_DAD_FAILURE: IPv6 Duplicate Address Detected! IPv6 DAD failed on vlan10
But this is not the case, since the error also remains with disabled DAD.
Versions of the physical S4148T:
TOR1# show version
Dell EMC Networking OS10 Enterprise
Copyright (c) 1999-2020 by Dell Inc. All Rights Reserved.
OS Version: 10.5.1.1P1
Build Version: 10.5.1.1P1.149
Build Time: 2020-04-06T15:57:33+0000
System Type: S4148T-ON
Architecture: x86_64
Up Time: 00:17:42
TOR2# show version
Dell EMC Networking OS10 Enterprise
Copyright (c) 1999-2020 by Dell Inc. All Rights Reserved.
OS Version: 10.5.1.1P1
Build Version: 10.5.1.1P1.149
Build Time: 2020-04-06T15:57:33+0000
System Type: S4148T-ON
Architecture: x86_64
Up Time: 00:12:31
DeweyBeck
2 Posts
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July 30th, 2020 23:00
I got sufficient information from your soul of heart.Thank you so much
John G
1 Message
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August 10th, 2021 06:00
I got a similar problem with my pair of S5232 except that I wanted fe80::1 to be the virtual-address.
How is ipv6 nd send-ra intended to be configured when using vrrp?
DELL-Erman O
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August 10th, 2021 23:00
Hello,
If possible, could you private message me the service tag of the switch and which country the switch is located in? I will be checking.
DELL-Erman O
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August 11th, 2021 03:00
Hi again,
Please find short explanation of how VRRP will work with IPV6 SLAAC.
Each router will send its link-local RA instead of VRRP ipv6 VIP, so if autoconfig is enabled, unfortunately, OS10 won't use VRRP VIP for ipv6 router advertisements, so failover will be depended on ipv6 stack convergence
In nutshell, when autoconfig is on, the host will receive IPV6 advertisement pointing to link-local address of router and not to IPV6 VRRP VIP.
Hope this will help!