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Michael Vincent
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Michael Vincent is an experienced network architect capable of delivering the full range of the network life cycle. Michael has extensive experience in small to large campus and internetwork design in both the enterprise and carrier space. Michael’s technical expertise encompasses most LAN and WAN protocols and media and the convergence of voice, video storage and data. Michael’s consulting skills link business needs with technical solutions to provide successful engagements and on-time delivery to the client.
Michael Vincent is an experienced network architect capable of delivering the full range of the network life cycle. Michael has extensive experience in small to large campus and internetwork design in both the enterprise and carrier space. Michael’s technical expertise encompasses most LAN and WAN protocols and media and the convergence of voice, video storage
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Member since
03-23-2009
25
Posts
28
Helpful
5
Solutions
04-27-2017
01:58 PM
You're tunneling IPv6 in IPv4, so the IPv4 will need a route between routers. Of course the FastEthernet interface works, it's directly connected.
Easiest option is static:
R1:
ip route 1.0.0.2 255.255.255.255 192.168.12.2
R2:
ip route 1.0.0.1 255.255.255.255 192.168.12.1
Cheers.
... View more
05-17-2016
01:31 AM
You're thinking of "unique local" which can be used, although I've never seen it bothered with.
It's actually fc00::/7, so you'd use:
fc00:: 134:23:33:22
Although I'm not sure that's what you want.
Visually, that "maps" to the IPv4 address, but logically, it doesn't given that IPv6 addresses are represented in hex. The logical mapping would be:
fc00::86 :17:21:16
In any case, including IPv4 addresses in IPv6 is bad practice (unless it's specifically a 'mapped' address for translation) since you'll be porting any bad IPv4 practices into your new IPv6 scheme.
Cheers.
... View more
12-22-2015
04:29 AM
Since all link local addresses start with fe80::/64, it's impossible to route for a machine with multiple interfaces - they all will have the same route. The interface appended tells the operating system which interface to send the traffic out. Note that once it's on the wire, it won't be routed off-net since it is link-local and no next-hop is defined.
See below, pinging (my defauilt gateway's link local address) without the interface results in destination unreachable, but appending the interface works:
----
VinsWorldcom @C:\Users\ VinsWorldcom > ping fe80::5a6d:8fff:fe78:ad40
Pinging fe80::5a6d:8fff:fe78:ad40 with 32 bytes of data: Destination host unreachable. Destination host unreachable.
Ping statistics for fe80::5a6d:8fff:fe78:ad40: Packets: Sent = 2, Received = 0, Lost = 2 (100% loss), Approximate round trip times in milli-seconds: Minimum = 3ms, Maximum = 3ms, Average = 3ms
VinsWorldcom@C:\Users\ VinsWorldcom > ping fe80::5a6d:8fff:fe78:ad40%11
Pinging fe80::5a6d:8fff:fe78:ad40%11 with 32 bytes of data: Reply from fe80::5a6d:8fff:fe78:ad40%11: time=40ms Reply from fe80::5a6d:8fff:fe78:ad40%11: time=1ms
Ping statistics for fe80::5a6d:8fff:fe78:ad40%11: Packets: Sent = 2, Received = 2, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 40ms, Average = 20ms
----
You can find the interfaces by using "netstat -rn"; the first number in the "Interface List" is the interface index number (the %# above):
----
VinsWorldcom @C:\Users\ VinsWorldcom > netstat -rn =================================================
Interface List
[...]
11...c0 cb 38 08 46 76 ......Dell Wireless 1397 WLAN Mini-Card 10...00 24 e8 9e f5 d7 ......Intel(R) 82567LM Gigabit Network Connection [...]
1...........................Software Loopback Interface 1 =================================================
[...]
----
Or get more detail with:
wmic path Win32_NetworkAdapter where "MACAddress IS NOT NULL" get Index,NetConnectionID,Description,MACAddress,GUID /format:list
Cheers.
... View more
11-06-2015
01:02 PM
Think of it this way:
How is 172.16.10.6 /30 in the 172.16.10.4 /30 subnet?
172.16.10.4 /30
172.16.10.5 /30
172.16.10.6 /30 <---
172.16.10.7 /30
You've done your subnetting in your question. The last nibble "6" is comprised of bits 60 - 63 in an IPv6 address. A mask of /62 leaves the last 2 bits (62, 63) for subnet. So:
nibble = bits 60, 61 | bits 62, 63
4 = 01 | 00
5 = 01 | 01
6 = 01 | 10 <---
7 = 01 | 11
Make sense?
... View more
05-13-2015
08:45 AM
IPv6 addresses beginning with 2002::/16 are special '6to4' addresses (see: http://en.wikipedia.org/wiki/6to4). The 6to4 address is created by appending the hex version of the IPv4 address to the '6to4' prefix: In your example: 2002:192.168.99.1::/64 2002:c0.a8.63.01::/64 2002:c0a8:6301::/64 The ::1 is simply the lower half 64-bits of the IPv6 address and can really be just about anything. So it is indeed the "interface ID" but can be calculated from various means including statically assigned.
... View more
04-24-2015
01:19 PM
FF1::1 is *not* the same as FF01::1. In fact, the first is not a valid IPv6 multicast address. See: http://www.iana.org/assignments/ipv6-multicast-addresses/ipv6-multicast-addresses.xhtml
... View more
04-12-2013
03:52 AM
They can't ping because they are not on the same subnet. NOTE: I'm assuming the second address you supplied ends in '0009' not '009' as in your post, although leading zero's don't really matter. Remember IPv6 addresses are in hex, so: HEX = Decimal 0009 = 9 0010 = 16 What you really want is: 2405:8a00:000a:0003:0000:0000:0000:0009 /126 2405:8a00:000a:0003:0000:0000:0000:000a /126 cheers.
... View more
02-22-2013
08:29 AM
Yes, you are correct and aren't missing anything. The author was a bit "sloppy" summarizing subnets that aren't actually in the aggregate. The author's aggregate summarizes: 3:: ... 3:ffff:ffff:ffff:ffff:ffff:ffff:ffff A bit more than just 3:1::, 3:2:: and 3:3::. Likewise, your example is a bit overreaching - technically. Your aggregate summarizes: 3:0:: 3:1:: 3:2:: 3:3:: Perhaps: 3:1::/64 3:2::/31 is more "technically" correct. I've been using /128's for loopback addresses all carved from a single /64. Just another way to do it. cheers.
... View more
01-11-2013
12:16 PM
I didn't develop 6to4 or 6rd so I can't say for sure "why" either one is the say they are, but 6rd addresses some of the shortcomings of 6to4 by not using a special prefix, allowing each 6rd operator to use their own prefix for better return-route control and removes the reliance on IPv4 anycast relays. The way I see it, 6rd is an improvement to 6to4 but also serves a slightly different purpose. Frankly, I've never used 6to4 as it was intended for host to router tunneling because all my hosts have private IPv4 space - so 6to4 won't work. I've used 6to4 for dynamic tunnels over IPv4-only MPLS networks for example, but that routing stays local to the client so no worry about polluting global routing tables.
... View more
01-11-2013
07:31 AM
The 6to4 2002::/16 special prefix is used for dynamic 6to4 tunnels. A full 6to4 address is created by using the 6to4 prefix (2002::/16) and the existing IPv4 interface address. So for example, my Windows host has a public IPv4 address of 198.133.219.25 (it doesn't really - that's what cisco.com resolves to for me, but this is only an example). My 6to4 address would be 2002:198.133.219.25::, or written more appropriately as: 2002:c685:db19:: (that's 198 = c6, 133 = 85 ...). So now I start using IPv6 over my 6to4 tunnel to the 6to4 anycast relay (192.88.99.1). Suppose my 198.133.219.25 is a class C subnet (/24) and all my colleages on that network - we'll say 200 of them to be conservative - also start using 6to4 with their public IPv4 address on that subnet. If 6to4 relay routers advertised more specifics, say to /48, they would now be advertising: 2002:c685:db19:: /48 2002:c685:db1a:: /48 2002:c685:db1b:: /48 2002:c685:db1c:: /48 2002:c685:db1d:: /48 ... All 200 - in effect host routes - for each one of my colleagues using 6to4. IPv6 routers' routing tables "polluted" with "IPv4" routes (the more specific 6to4 prefixes). I may also lose the advantage of the anycast relay routers as my IPv6 prefix would be "tied" to the 6to4 relay router advertising my more specific route. Hope that helps.
... View more
12-20-2012
09:47 AM
See here: http://www.cisco.com/en/US/docs/switches/datacenter/sw/nx-os/multicast/configuration/guide/b_multicast_chapter_0100.html "When OMF is disabled, unknown IPv4 multicast traffic and all IPv6 multicast traffic is flooded to all ports in the VLAN. (Unknown multicast traffic refers to multicast packets that have an active source, but have no receivers in the ingress VLAN. Having no receivers means that there is no group forwarding entry in the hardware.)" Depending on your design and configuration, this may not be a problem if the source is routed to an RP or your sources sit in appropriately sized VLANs (based on IP(v6) mask and/or number of hosts). With IPv4, our multicast sources are on their own /27. With IPv6, they'd live on a /64, but you can limit the hosts on that network to multicast source only and keep the number low so traffic won't impact other hosts / servers. cheers.
... View more
11-21-2012
06:05 AM
6VPE is a tunneling technology to allow you to run IPv4 and IPv6 over an IPv4-only core and provide dual-stack at the customer edge. The customer is blissfully unaware that there is anything other than dual-stack - or better described as IPv4 and IPv6 capabilities - at their demarcation. If you configure your entire core with dual-stack, there isn't really a need for 6VPE. What you will need is a solution for LDPv6 or what is sometimes referred to as MPLSv6 ( http://blogs.cisco.com/tag/ldpv6/ ). cheers.
... View more
11-09-2012
04:05 AM
For MPLS VPNs and IPv6, you'll want to look at using the 6VPE technology described in RFC 4659. There are a ton of Internet resources for what it does and how to go about implementing. Basically, 6VPE will allow dual-stack at the CE devices while still maintaining an IPv4 MPLS core. IPv6 routes are carried in BGP address families (vpnv6) and make use of IPv4-mapped IPv6 addresses to meet the next hop requirements. A very basic playbook (again, many Intenet resources - including Cisco - can provide detail): 1) Configure VPNV6 address family between PE routers 2) Ensure / update VRFs to use address-families 3) Add IPv6 addressing to the PE / CE link 4) Update CE BGP configurations for dual-stack / address families cheers.
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10-11-2012
05:22 AM
In your scenario, R1 and R2 will talk - they are both IPv4. R2 and R3 on the other hand won't talk as R2 is IPv4 and R3 is IPv6. R1 should be running both IPv4 and IPv6, although not necessarily dual-stack - both IPv4 and IPv6 on both interfaces (to R2 and R3). If R2 and R3 indeed really need to communicate, you can dual stack the interfaces on R1 - put an IPv6 address on the R1 interface to R2 (and give R2 a corresponding IPv6 address) and put an IPv4 address on the R1 interface to R3 (and give R3 a corresponding IPv4 address). The only way to have an IPv4 host talk to an IPv6 host is through some sort of translation technique (NAT-PT (deprecated), DNS64/NAT64, SLB64, AFT ...). cheers.
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10-07-2012
04:56 AM
There is no such thing as broadcasts in IPv6 - only unicast, multicast and anycast. So broadcast storms are not a concern on networks. However, the physical limitations of a contention based media will certainly impose a pragmatic limit the number of acual nodes. And that limit may be different based on network type - e.g., end users versus a data center server tier. IPv6 isn't designed to support 2^64 hosts per subnet, per se - although theoretically, if you had 2^64 hosts sitting around, you could get them all addressed on a single IPv6 subnet. For those of us with long time experience with IPv4 - seeing /24 and even /16 in some cases used on point-to-point links, using IPv6 a single /64 broken in to /126 subnets for point-to-point links will provide more than enough networks to address all your point-to-point links. On the LAN side however, there are some protocols (ND, RS, SLAAC) that rely on /64, so while you can put the subnet boundary where ever you want, you'll really want to stick with /64. cheers.
... View more
04-27-2017
You're tunneling IPv6 in IPv4, so the IPv4 will need a route between
routers. Of course the FastEthe...
05-17-2016
You're thinking of "unique local" which can be used, although I've never
seen it bothered with. It's...
12-22-2015
Since all link local addresses start with fe80::/64, it's impossible to
route for a machine with mul...
11-06-2015
Think of it this way: How is 172.16.10.6 /30 in the 172.16.10.4 /30
subnet? 172.16.10.4 /30 172.16.1...
05-13-2015
IPv6 addresses beginning with 2002::/16 are special '6to4' addresses
(see: http://en.wikipedia.org/w...
04-24-2015
FF1::1 is *not* the same as FF01::1. In fact, the first is not a valid
IPv6 multicast address. See:
...
04-12-2013
They can't ping because they are not on the same subnet.NOTE: I'm
assuming the second address you su...
02-22-2013
Yes, you are correct and aren't missing anything. The author was a bit
"sloppy" summarizing subnets ...
Created by
Michael Vincent
in IPv6
01-11-2013
01-11-2013
I didn't develop 6to4 or 6rd so I can't say for sure "why" either one is
the say they are, but 6rd a...
Created by
Michael Vincent
in IPv6
01-11-2013
01-11-2013
The 6to4 2002::/16 special prefix is used for dynamic 6to4 tunnels. A
full 6to4 address is created b...
Created by
Michael Vincent
in IPv6
12-20-2012
12-20-2012
See
here:http://www.cisco.com/en/US/docs/switches/datacenter/sw/nx-os/multicast/configuration/guide/...
11-21-2012
6VPE is a tunneling technology to allow you to run IPv4 and IPv6 over an
IPv4-only core and provide ...
11-09-2012
For MPLS VPNs and IPv6, you'll want to look at using the 6VPE technology
described in RFC 4659. Ther...
10-11-2012
In your scenario, R1 and R2 will talk - they are both IPv4. R2 and R3 on
the other hand won't talk a...
Public Statistics
| Date Registered | 03-23-2009 07:40 AM |
| Date Last Visited | 06-27-2018 12:18 AM |
| Total Messages Posted | 25 |
| Total Helpful Votes Received | 28 |
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