I think that 161.164.248.0/21 and AS 28551 may be hijacked.
To summarize
AS 28551 is announcing 161.164.248.0/21
28551 is assigned to LANIC but has not been assigned to a end user.
161.164.248.0/21 is assigned to WalMart
161.164.248.0/21 is currently routed through AS35681 - VINDAVA-AS - which is in Bucharest, Romania
I think that this is a bogon.
Regards
Marshall
P.S. I have asked WalMart about this, and received no response.
traceroute to 161.164.248.1 (161.164.248.1), 64 hops max, 40 byte packets
<snip>
7 tengige0-3-0-3.auvtr1.Aubervilliers.opentransit.net (193.251.241.253) 78.728 ms 79.154 ms 79.548 ms
8 tengige0-3-0-1.ffttr1.FrankfurtAmMain.opentransit.net (193.251.241.254) 85.894 ms 86.476 ms 86.701 ms
9 64.208.110.229 (64.208.110.229) 86.312 ms 87.509 ms 87.463 ms
10 Alestra-S-De-R-L-De-CV-San-Pedro-Garza.so-0-2-0.ar1.MEX1.gblx.net (208.48.33.78) 266.280 ms Alestra-S-De-R-L-De-CV-Lago-Zurich.so-0-2-2.ar1.MEX1.gblx.net (64.215.25.70) 262.566 ms Alestra-S-De-R-L-De-CV-San-Pedro-Garza.so-1-1-0.ar1.MEX1.gblx.net (208.48.238.98) 473.559 ms
11 host-201-151-29-61.block.alestra.net.mx (201.151.29.61) 260.021 ms 433.502 ms 259.899 ms
12 host-201-151-29-42.block.alestra.net.mx (201.151.29.42) 661.863 ms 256.985 ms 434.032 ms
13 * * *
As well AS paths shown from route-views.ip.att.net end with AS11172 (alestra) then AS28551.
Perhaps Walmart is providing Internet access for its maquilladoras? 
Cheers,
-w