Trace/tcptrace to 108.174.2.129 via Level3 - last hop is on the Linked/Level3 edge:
14 LINKEDIN-CO.edge3.Washington4.Level3.net (4.53.116.150) 76.034 ms 76.069 ms 76.066 ms
Via telia.net
16 236 ms 221 ms * linkedin-ic-301441-ash-b1.c.telia.net [213.248.103.190]
17 * * * Request timed out.
18 259 ms 265 ms * 108.174.2.129
19 257 ms 299 ms 256 ms 108.174.2.129
No reply from LinkedIn support, but i see plenty of Verizon and Level3 customers cannot access LinkedIn for 24 hrs.
216.52.242.113 works ok.
-SC (ASN25605)
Stuart,
You don't tell us if it's www.linkedin.com or linkedin.com, but in any case,
because they serve up that site around the world using some form of GLB it
may resolve to different IP depending on where you are. From my perspective
it is working via Cogent, and I can hit 108.174.2.129, too:
root@nagios:# tcptraceroute www.linkedin.com
Selected device eth0.3, address 96.31.0.5, port 43355 for outgoing packets
Tracing the path to www.linkedin.com (199.101.163.129) on TCP port 80 (www),
30 hops max
1 router-core-inside.mtcnet.net (96.31.0.254) 0.253 ms 0.193 ms 0.203
ms
2 sxct.sxcy.mtcnet.net (167.142.156.197) 0.194 ms 0.131 ms 0.129 ms
3 premier.sxcy-mlx.fbnt.netins.net (173.215.60.5) 1.632 ms 1.601 ms
1.583 ms
4 38.104.184.26 7.004 ms 6.373 ms 6.437 ms
5 te0-0-1-1.rcr11.dsm01.atlas.cogentco.com (38.104.184.25) 5.913 ms
6.083 ms 5.877 ms
6 te0-2-0-0.ccr41.ord01.atlas.cogentco.com (154.54.46.237) 13.057 ms
13.114 ms 13.075 ms
7 be2156.ccr21.mci01.atlas.cogentco.com (154.54.6.85) 24.995 ms 24.942
ms 25.053 ms
8 be2012.ccr21.dfw01.atlas.cogentco.com (154.54.2.114) 35.013 ms 34.942
ms 34.928 ms
9 be2144.ccr21.iah01.atlas.cogentco.com (154.54.25.105) 40.455 ms 40.749
ms 40.709 ms
10 be2065.ccr21.lax01.atlas.cogentco.com (154.54.5.66) 76.269 ms 76.119
ms 75.970 ms
11 * * *
12 154.24.22.126 76.351 ms 76.296 ms 76.257 ms
13 38.88.244.2 73.135 ms 73.101 ms 73.182 ms
14 border1.po1-20g-bbnet1.lax008.pnap.net (216.52.255.46) 73.354 ms
73.355 ms 73.585 ms
15 linkedin-16.border1.lax008.pnap.net (216.52.220.122) 74.017 ms 74.005
ms 73.965 ms
16 * * *
17 199.101.162.226 74.766 ms 74.391 ms 74.582 ms
18 199.101.163.129 [open] 74.528 ms 74.381 ms 74.421 ms
root@nagios:#
root@nagios:/# tcptraceroute 108.174.2.129
Selected device eth0.3, address 96.31.0.5, port 49338 for outgoing packets
Tracing the path to 108.174.2.129 on TCP port 80 (www), 30 hops max
1 router-core-inside.mtcnet.net (96.31.0.254) 0.295 ms 0.210 ms 0.237
ms
2 sxct.spnc.mtcnet.net (167.142.156.194) 0.206 ms 0.144 ms 0.129 ms
3 premier.spnc-mlx.fbnt.netins.net (173.215.60.1) 15.282 ms 4.743 ms
4.750 ms
4 ins-kb3-et-0-7-0-0.kmrr.netins.net.67.142.167.in-addr.arpa
(167.142.67.50) 8.787 ms 8.705 ms 8.505 ms
5 ins-kc2-et-9-3.kmrr.netins.net (167.142.67.49) 7.170 ms 7.183 ms
7.189 ms
6 ins-dc1-po20.desm.netins.net (167.142.67.29) 7.623 ms 8.936 ms 8.135
ms
7 207.87.180.149 12.733 ms 52.226 ms 12.740 ms
8 ae1d0.mcr1.minneapolis-mn.us.xo.net (216.156.1.85) 23.368 ms 22.132 ms
22.052 ms
9 vb1710.rar3.chicago-il.us.xo.net (216.156.0.169) 22.984 ms 23.536 ms
24.016 ms
10 207.88.14.194.ptr.us.xo.net (207.88.14.194) 21.861 ms 21.882 ms
21.880 ms
11 206.111.2.65.ptr.us.xo.net (206.111.2.65) 23.583 ms 22.722 ms 22.876
ms
12 ae-8.r05.chcgil09.us.bb.gin.ntt.net (129.250.4.221) 22.630 ms 22.751
ms 22.817 ms
13 165.254.191.82 22.760 ms 22.726 ms 22.722 ms
14 * * *
15 * * *
16 108.174.2.129 [open] 36.065 ms 36.058 ms 36.042 ms
root@nagios:/#
root@nagios:/usr/lib/nagios/plugins# ./check_http -H www.linkedin.com -I
199.101.163.129
HTTP OK: HTTP/1.1 301 Moved Permanently - 1706 bytes in 0.167 second
response time |time=0.166917s;;;0.000000 size=1706B;;;0
root@nagios:/usr/lib/nagios/plugins#
root@nagios:/usr/lib/nagios/plugins# ./check_http -H www.linkedin.com -I
108.174.2.129
HTTP OK: HTTP/1.1 301 Moved Permanently - 1702 bytes in 0.088 second
response time |time=0.088261s;;;0.000000 size=1702B;;;0
root@nagios:/usr/lib/nagios/plugins#
Regards,
Frank
Thanks Frank - www.linkedin.com is the one i see problems with testing from two locations UK and Frankfurt. London TR is below.
If i jump out of our AMS location (ASN109 - via AS1299 ) i dont see any problems.
[root@ops-netops-util1 ~]# tcptraceroute linkedin.com
Selected device eth0, address 10.3.4.38, port 42311 for outgoing packets
Tracing the path to linkedin.com (216.52.242.86) on TCP port 80 (http), 30 hops max
6 xe-5-0-0.edge5.London1.Level3.net (212.187.138.209) 1.078 ms 1.040 ms 1.159 ms
7 * * *
8 ae-56-221.ebr2.London1.Level3.net (4.69.153.129) 76.147 ms 75.863 ms 75.901 ms
9 * * *
10 * * *
11 ae-48-48.ebr2.Washington1.Level3.net (4.69.202.61) 75.557 ms 75.550 ms 75.511 ms
12 ae-82-82.csw3.Washington1.Level3.net (4.69.134.154) 75.700 ms 75.502 ms 75.644 ms
13 ae-3-80.edge3.Washington4.Level3.net (4.69.149.146) 75.639 ms 75.726 ms 75.692 ms
14 LINKEDIN-CO.edge3.Washington4.Level3.net (4.53.116.150) 75.888 ms 75.924 ms 75.912 ms
15 * * *
16 * * *
17 * * *
18 * * *
19 199.101.162.230 149.661 ms 151.158 ms 149.616 ms
20 careers.linkedin.com (216.52.242.86) [open] 149.264 ms 149.369 ms 149.448 ms
[root@ops-netops-util1 ~]# tcptraceroute www.linkedin.com
Selected device eth0, address 10.3.4.38, port 57760 for outgoing packets
Tracing the path to www.linkedin.com (108.174.2.129) on TCP port 80 (http), 30 hops max
5 xe-5-0-0.edge5.London1.Level3.net (212.187.138.209) 1.060 ms 1.082 ms 1.041 ms
6 * * *
7 ae-58-223.ebr2.London1.Level3.net (4.69.153.137) 75.830 ms 75.929 ms 75.739 ms
8 * * *
9 * * *
10 ae-47-47.ebr2.Washington1.Level3.net (4.69.202.57) 75.950 ms 76.001 ms 75.942 ms
11 * ae-82-82.csw3.Washington1.Level3.net (4.69.134.154) 75.713 ms 75.589 ms
12 ae-3-80.edge3.Washington4.Level3.net (4.69.149.146) 75.702 ms 75.769 ms 75.748 ms
13 LINKEDIN-CO.edge3.Washington4.Level3.net (4.53.116.150) 75.973 ms 75.924 ms 76.664 ms
14 * * *
15 * * *
[timesouts]
Cheers!
-SC (ASN25605)
Stuart, I believe someone from our support desk has reached out to you. If you still need help reply to me off list.
Zaid
Stuart,
You haven't shared your IPs but you could go to Level3's Washington Looking
Glass and see if you can trace back to your UK and Frankfurt IPs.
Frank
Frank,
Reverse is ok from L3's looking glass in Washington. SRC prefix for our London DC is 108.171.128.0/24.
Cheers!
I am still seeing plenty of spam from them, so I believe they are up.
//warren
I would cry for about 37 seconds if LinkedIn went down permanently. Then, get over it and not worry about their spam. Signed up when they first started but stopped using almost immediately when they kept requesting permission to access my contacts.
matthew black
[Note: speaking only for myself and not my employer or anyone else]
I took a picture of my wife for my her profile on my phone, and it ended up on a profile they created for her. She has no idea what LinkedIn is, but she's got a profile and a picture.
I wanted to like them, but they are simply douchebags. They give zero thought to how their customer would want to be treated and they consume your entire life.
I can't wait to see them at a trade show or get an email about the class action someone is filing soon.
And if you're from LinkedIn and reading this.. Quit now and save your soul. Your employer makes the Internet a less valuable tool by degrading it into some mega corporate data fleecing machine.
Have a good week....! 
Speaking for all rational people who expect a "social media" website to stay in their lane.
--As of August 18, 2014 3:44:09 PM +0000, Warren Bailey is alleged to have said:
I took a picture of my wife for my her profile on my phone, and it ended
up on a profile they created for her. She has no idea what LinkedIn is,
but she's got a profile and a picture.
I wanted to like them, but they are simply douchebags. They give zero
thought to how their customer would want to be treated and they consume
your entire life.
I can't wait to see them at a trade show or get an email about the class
action someone is filing soon.
And if you're from LinkedIn and reading this.. Quit now and save your
soul. Your employer makes the Internet a less valuable tool by degrading
it into some mega corporate data fleecing machine.
Have a good week....! 
Speaking for all rational people who expect a "social media" website to
stay in their lane.
--As for the rest, it is mine.
To everyone who feels this way, and has *some* influence: Please tell your HR people this as well. I've been searching for a job for months, and getting a LinkedIn account is 'highly recommended' by most job agencies, and outright *required* for application to some companies.
Complaining here is complaining to the choir. Talk to the people who think it's a useful tool and are requiring other people to use it, against their own better judgment.
Daniel T. Staal