Questions tagged [ipv6]
For questions about Internet Protocol version 6 (IPv6); as specified in RFC 8200.
474
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Why is EUI-48 to EUI-64 conversion deprecated, and yet it's used in IPv6?
The IEEE Guidelines for Use of Extended Unique Identifier (EUI), Organizationally Unique Identifier (OUI), and Company ID (CID) [PDF] have a section titled, "Mapping an EUI-48 to an EUI-64". ...
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17
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Finding the IPv6 -> IPv4 gateway [closed]
I am writing a program to accommodate a customer who has IPv4 sites that have no DNS name (that we're aware of, anyway), and I need to be able to reach the sites from a mobile network carrier that ...
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44
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What is hiearchy of IP addresses? [duplicate]
What is structure/hiearchy of IP addresses?
I mean, is mandatory that IP address e.g. 216.9.10.0 is subnet of 216.9.0.0? Of course many times that is the case and IMO it would be logical, but I have ...
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38
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Should (IPv6) multicast subscribers send report to query?
I am waking through RFC3810 and playing with MLDv2.
From that RFC I thought when anyone send query for group :: (all groups) and send it to address ff02::1 all subscribers on segment should send its ...
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4
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2
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589
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must an IPv6 router have an IP address in the SLAAC prefixes it's advertising?
for example: i have a router with the lladdr fe80::1/64 on interface e0. the router is configured to advertise the autonomous, on-link prefix 2001:db8:1:1::/64 in RAs on e0. must the router have an ...
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1
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66
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Get all reachable IP addresses within a private network [closed]
Is there a way to get all reachable IP addresses within a private network. I know that we can get all active devices' IP addresses within same subnet using arp.
I was wondering if something similar ...
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1
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88
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ipv6 - SLAAC - proper handling of RA in case of already existing prefix
I have a device which, apart from SLAAC, can also get an IPv6 address (IP) on interface by manual configuration.
How the device should behave, when it gets a RA packet with prefix equal to the IP's ...
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252
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MTU for WireGuard over IPv6
What would be the optional MTU for a virtual WireGuard link transmitting over IPv6 to avoid unnecessary fragmentation?
Here is how I approached the calculation:
[IPv6 Header] - 40 bytes
[Some IPv6 ...
0
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1
answer
35
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IPv6 subnetting with different end device requirements
`I have three main buildings with building A with 242 end devices, building B with 54 end devices and building C with 894 device. And all the routers are connected to each other like ring topology. ...
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2
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2
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145
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Can link-local address be used by DHCPv6 Relay
So I will start that I read this previous post here:
Can link local addresses be used for transit networks without breaking routability?
But it's not fully registering in my brain I guess if this ...
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How to configure ipv6 static route for cisco router
I've tried but i don't know if i got it right. So per the picture, If i want to set a static route from R1 to SW1 subnet The command should be ipv6 route 2001:d79:1:345::/64 2001:d79:1:13::
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2
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Is there any reason to use unique local IPv6 addreses in a production network?
The title pretty much explains everyrthing.
Since there is a huge amount of IPv6 addresess, couldn't every device just use a global unicast address? What is the practical use of unique local IPv6 ...
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2
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785
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Is possible to use DHCPv6 without SLAAC?
Hello may (legally) occur situation when router is not sending router advertisements but is providing configuration via DHCPv6?
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Can, and should, a link local address be used for a gateway in IPv4? [closed]
I was just experimenting with IPv6 and hypervisors, where I made productive use of the IPv6 link local address to route packets towards a tap device to establish communication with a virtual machine.
...
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1
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For IPv6, How much processing delay difference between using /64 and /127 for Core network interconnection?
I've question about IPv6 routing processing delay.
Lets assume we've got big Core network with huge traffic and many hops.
All router's p2p interconnection addresses are used /127 network.
In my ...
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2
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58
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Huawei Cloudengine 6851 ipv6 acl not matching
I have a Huawei 6851 and this is my config
acl ipv6 number 3006
description MY-IPv6
rule 10 permit ipv6 source 2001:x:x:x::x:x/112
rule 20 deny ipv6 destination 2001:x:x:x::x:y/128
rule 30 permit ipv6
...
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0
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2
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106
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Customized IPv6 packet with multiple inner data fragments for multiple destinations
I am studying the possibilities of using IPv6 potentialities to design a customized IPv6 data packet that has the following features:
1. Combines many fragments of different data in one packet.
For ...
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1
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1
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543
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The use of a link local IPv6 address
In a networking course that I'm following, there was a mention of several ways of how IPv6 link local addresses can be used, such as
Assigning the link local address of a router/L3 switch as the ...
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1
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204
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OSPFv3 Convergence Issue between OPNSense & Cisco Router
I have been digging around the internet and have been trying to get IPv6 up and running on my lab. Here is my current layout:
I have been trying to get OPNSense and the Cisco 1900 router to give each ...
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0
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Identify first six /49 blocks out of ABCD::/32 [duplicate]
The answer is given as
ABCD:0000:0000:0000:0000::/49
ABCD:0000:0000:0000:8000::/49
ABCD:0000:0000:0001:0000::/49
ABCD:0000:0000:0001:8000::/49
ABCD:0000:0000:0002:0000::/49
ABCD:0000:0000:0002:8000::/...
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I am trying to wrap my head around NDP
I know before PC10 can ping PC11 it will use IPv6 Neighbor Discovery to resolve the Destination MAC address for layer 2 header.
But what would the DEST MAC ADDR be and what topics can I learn this
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How to correctly setup a DHCP server in the following network?
So, I've got the following Network Configuration:
Assume that, on the graph, "PCs" can be any device that needs an IP(apart from a router).
Now, as explained on my title, I want to run a ...
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1
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0
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60
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A new pattern of IPv6 addresses in mobile network [closed]
When I checked the IPv6 addresses in a mobile network from the log, I found a strange IPv6 IID configuration pattern. As shown below, the common part of the IID of IPv6 addresses is :1:0:.
2401:4900:...
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1
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129
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Many SYN_RECV connections in netstat [closed]
When I do netstat -tn, I consistently see a lot of connections from a few ipv6 addresses (the fe80:: ones; usually around or exactly 4096 of them). I'm unable to find the addresses on WHOIS, and ...
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2
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683
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Can a jumbogram (giant data packet) be used at a large scale (in WAN for example)?
There are many scientific paper for Jumbo frame, even more, some real implementations and deployments. But it is not the case for Jumbogram !!
Jumbo frame (geant frame) for Layer 2; Jumbogram (geant ...
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17
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5
answers
5k
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Why do we need ports with IPv6?
My understanding is there are 2^32 - 1 possible IPv4 addresses, and 2^16 - 1 possible ports. Which gives ~2^48 addresses.
The additional 2^16 additional ports seem almost insignificant considering the ...
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93
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IPv6-over-IEEE802.15.4 Multicast scope
An IPv6 Multicast address is defined as
| 8 | 4 | 4 | 112 bits |
+--------+----+----+-------------------------------------+
|11111111|flgs|scop| group ID ...
1
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2
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613
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IPv6 subnets without delegated prefix
I have received an IPv6 network from my provider, say it's 2001:db8:1::/48.
I did not get delegated prefix from them.
I would like to use the IPv6 addresses on different networks behind a firewall (...
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0
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16
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What is the maximum safe UDP payload size over IPv6? [duplicate]
I am developing a networking library (that uses exclusively UDP) and I want to support both IPv4 and IPv6 by using a dual-mode socket. I want to limit the size of the packet user can send to a value ...
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1
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253
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Does Network Discovery (rfc2461) preclude ARP sniffing?
I'm debugging a system demonstrating intermittent loss of connection. It's loosing entries from the neighborhood cache while there are active connections.
Does Neighbor Discovery (rfc2461) require ...
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2
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88
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Simple IPv6 Global Unicast question
I was reading this article which states:
RFC 3587 states that out of the 128 bits in IPv6 addresses, left most
three bits are must be fixed as 001. Remaining 45 bits are reserved
for global routing ...
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2
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284
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Will there be an easy way to identify local Ipv6 addresses like with Ipv4?
When using WireShark, WNetWatcher, or any packet analysis tool, it's very easy "at a glance" to identify packets that are originating from the local network versus the Internet, since their ...
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1
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731
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Understand DSCP and Precedence Values in Ipv4 or Ipv6 packet
I read from this website to understand DSCP and it's corresponding IP precedence value.
For example DSCP value is '000 000' which Drop Probability is N/A(never happen) and it's Equivalent IP ...
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1
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42
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Does socket address include transport protocol (http://)? [closed]
Let's say I have the following: http://ip_addr:port
This is supposedly called the socket address (see sources below), but I can't find a conclusive answer anywhere if the transport protocol (http://) ...
1
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0
answers
81
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How do I set up IPv6 multicast over an MPLS carrier?
I'm setting up an MPLS carrier with VPNs in GNS3, using Cisco 7200 routers.
Exact version I'm using is C7200-ADVIPSERVICESK9-M Version 15.2(4)S5, but I'm willing to upgrade/change if that's needed.
On ...
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2
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1
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Which ranges of IPv6 and IPv4 do requests to the local network and the host?
I'm looking for the range of IP address that is bound to the local network or the host itself.
So far for IPv4 I found:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255....
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2
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IPv6 Subnetworks Explanation
Can somebody help me get a better understanding of IPv6? For me, v4 is considerably easier to wrap your head around. Some questions I still have after a few hours of reading:
Maybe the simplest one: ...
1
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1
answer
68
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What "IVI" from "IVI Translation" stands for?
In several documents in the context of IPv4/IPv6 transition I see these three letters "IVI" that seems to be an acronym, but I was unable to find what it means or suppose to refer.
Maybe is ...
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1
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188
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Is an ICMPv6 neighbor advertisement meaningful if no options are set?
This is what I think a normal ICMPv6 neighbor advertisement should look like:
It says "I'm 2001:57a:d000::54 and you can reach me at 02:02:53:85:21:25". This is what neighbor advertisements ...
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2
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How does all 54bits after FE80/10 should be set to 0 apply?
I read on a website: " link local addresses use the address block of Fe80::/10 (from FE80:: to FE80:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF). However, the standard states that the 54 bits after FE80/...
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IPv6 prefix interpretation
I have a very basic question about IPv6 prefix. Taking a very simple example about prefix notation:
"2001:db8:abcd:0012::0/64"
My question is:
Do we call the whole thing under quote as ...
3
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1
answer
574
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IPv6 neighbour discovery blocked by MLD snooping switch
I recently noticed that my IPv6 multicast traffic was being broadcasted to all hosts connected to a switch, even those that had not subscribed to the traffic.
To fix this, I enabled MLD snooping on ...
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1
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1
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79
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OSPFv3 Authentication IPSEC SPI/Logging issues - Can you filter out logs?
I'm running into a problem with our Cisco ASR-1002HX and ASR-1006X. I have a mix of Juniper and Cisco routers all configured exclusively with IPv6. All of our routers are in the same ospfv3 area 0. We ...
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2
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619
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IPv6 link-local address
Can somebody explain why we can assign link-local address FE80::1 to both interfaces?
What does it give to me ?
R1(config)# interface g0/0
R1(config-if)# ipv6 address fe80::1 link-local
R1(config-if)# ...
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1
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775
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Is it possible to do SLAAC with Route Advertisement *without* default-route? [closed]
I have a router with IPv6-ULA networks. It's running Linux with Systemd-networkd if that matters.
Now I'd like to auto-configure clients in one network so that they will have an address in one of the ...
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1
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1
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320
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Why solicited-node multicast address while all-node multicast address can do the same thing?
Why bother plugging in the last 24 bits of the sender's unicast address into the solicited-node multicast address while all-node multicast address can achieve the same thing? In my view, this move is ...
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2
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2
answers
194
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Does it require a DAD when generating link-local address in IPv6
In IPv4, link-local addresses are checked to be unique using an ARP request. But in IPv6, as it is generated by a EUI-64 or hash. It is assumed to be unique (I suppose). But does it require a DAD (...
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95
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What is the reason behind not returning unused IP addresses? [closed]
There are several companies out there with one or more /8 IP addresses, for example:
DoD has more than 200 million,
HP has one /8 (>16 million),
Apple has one /8,
General Electric has one /8,
IBM ...
- 103
1
vote
2
answers
608
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Calculating Checksum for ICMPv6 Packet
I have a packet that has a checksum of 0xffff, and a calculated checksum of 0x0000. I know in UDP, a checksum of 0x0000 is not allowed, and is instead replaced with 0xffff, thus the packet should be ...
user80254
1
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5
answers
648
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If IPv6 exists, why do we still pay for static IPv4 addresses?
Given that there is some ridiculous number of IPv6 addresses per every single person on the planet, why do ISPs still charge for IPv4 addresses? Why not just give the user an IPv6 address?
Is it ...
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